Chicago River
River
Chicago River Main Stem at dusk in January 2008 (viewed looking east from Wolf Point)
Country	United States
State	Illinois
City	Chicago
Source	Lake Michigan
Length	156 mi (251 km)
Map of the Chicago River
Wikimedia Commons: Chicago River

The Chicago River is a system of rivers and canals with a combined length of 156 miles (251 km)^[1] that runs through the city of the same name, including its center (the Chicago Loop). Though not especially long, the river is notable for being the reason why Chicago became an important location, as the link between the Great Lakes and the Mississippi Valley waterways. In the 19th century through civil engineering, the flow of the river was reversed to head toward the Mississippi River basin, away from Lake Michigan, into which it previously emptied. This was done for reasons of sanitation. The river is also noted for the local custom of dyeing it green on St. Patrick's Day.

The river is memorialized, in part, by two horizontal blue stripes on the Municipal Flag of Chicago.^[2] The river also serves as inspiration for one of Chicago's ubiquitous symbols: a three-branched, Y-shaped symbol (called the municipal device) is found on many buildings and other structures throughout Chicago; it represents the three branches of the Chicago River.^[3][4]

Course[link]

A view of the Chicago River from the South Branch, looking toward the Main Stem (right) and the North Branch (upper left) at Wolf Point

When it followed its natural course, the North and South Branches of the Chicago River converged at Wolf Point to form the Main Stem, which jogged southward from the present course of the river to avoid a baymouth bar entering Lake Michigan at about the level of present day Madison Street.^[5] Today, the Main Stem of the Chicago River flows west from Lake Michigan to Wolf Point, where it converges with the North Branch to form the South Branch, which flows south west and empties into the Chicago Sanitary and Ship Canal.

North Branch[link]

Early settlers named the North Branch of the Chicago River the Guarie River, or Gary's River, after a trader who may have settled west bank of the river a short distance north of Wolf Point, at what is now Fulton Street.^[6][7] The source of the North Branch is in the northern suburbs of Chicago where its three principal tributaries converge. The Skokie River—or East Fork—rises from a flat area, historically a wetland, near Park City, Illinois to the west of the city of Waukegan.^[8] It then flows southward, paralleling the edge of Lake Michigan, through wetlands, the Greenbelt Forest Preserve and a number of golf courses towards Highland Park, Illinois.^[9] South of Highland Park the river passes the Chicago Botanic Gardens and though an area of former marshlands known as the Skokie Lagoons. The Middle Fork arises near Rondout, Illinois and flows southwards through Lake Forest and Highland Park. These two tributaries merge at Watersmeet Woods west of Wilmette, from there the North Branch flows south towards Morton Grove.^[10] The West Fork rises near Mettawa and flows south through Bannockburn, Deerfield, and Northbrook, meeting the North Branch at Morton Grove.^[11]

CTA train and kayakers on the North Branch, from the Wilson Avenue bridge

The North Branch continues southwards though Niles, entering the city of Chicago near the intersection of Milwaukee Avenue and Devon Avenue,^[12] from where it serves as the boundary of the Forest Glen community area with Norwood Park and Jefferson Park. On this stretch of the river it meanders in a south-easterly direction, passing through golf courses and forest preserves until it reaches Foster Avenue, where it passes through residential neighborhoods on the north side of the Albany Park community area.^[13] In West River Park the river meets the North Shore Channel, a drainage canal built between 1907 and 1910 to increase the flow of the North Branch and help flush pollution into the Chicago Sanitary and Ship Canal. From the confluence with the North Shore Channel south to Belmont Avenue the North Branch flows through mostly residential neighborhoods in a man-made channel that was dug to straighten and deepen the river, helping it to carry the additional flow from the North Shore Channel.^[14]

South of Belmont the North Branch is lined with a mixture of residential developments, retail parks, and industry until it reaches the industrial area known as the Clybourn Corridor.^[15] Here is passes beneath the Cortland Street Drawbridge, which was the first 'Chicago-style' fixed-trunnion bascule bridge built in the United States,^[16] and is designated as an ASCE Civil Engineering Landmark and a Chicago Landmark.

At North Avenue, south of the North Avenue Bridge, the North Branch divides, the original course of the river makes a curve along the west side of Goose Island, whilst the North Branch Canal cuts off the bend, forming the island. The North Branch Canal—or Ogden's Canal—was completed in 1857, and was originally 50 feet (15 m) wide and 10 feet (3.0 m) deep allowing craft navigating the river to avoid the bend.^[17] The 1902 Cherry Avenue Bridge, just south of North Avenue, was constructed to carry the Chicago, Milwaukee and St. Paul Railway onto Goose Island. It is rare example of an asymmetric bob-tail swing bridge^[18] and was designated a Chicago Landmark in 2007.^[19] From Goose Island the North Branch continues to flow south east to Wolf Point where it joins the Main Stem.

Main Stem[link]

The Main Stem of the river, Wrigley Building, and Tribune Tower at night.

The source of the Main Stem of the Chicago River is Lake Michigan. Water enters the river through sluice gates at the Chicago River Controlling Works with a small additional flow provided by the passage of boats between the river and Lake Michigan through the Chicago Lock.^[20] The surface level of the river is maintained at 0.5 to 2 feet (0.15 to 0.61 m) below the Chicago City Datum (579.48 feet [176.63 m] above mean sea level) except for when there is excessive storm run-off into the river or when the level of the lake is more than 2 feet below the Chicago City Datum.^[21] Acoustic velocity meters at the Columbus Drive Bridge and the T.J. O'Brien lock on the Calumet River monitor the diversion of water from Lake Michigan to the Mississippi River basin, which is limited to an average of 3,200 cubic feet (91 m³) per second per year over the 40 year period from 1980 to 2020.^[22]

View west along the Main Stem of the Chicago River from the Outer Drive Bridge, 2009

The Main Stem flows 1.5 miles (2.4 km) west from the controlling works at Lake Michigan;^[23] passing beneath the Outer Drive, Columbus Drive, Michigan Avenue, Wabash Avenue, State Street, Dearborn Street, Clark Street, La Salle Street, Wells Street, and Franklin Street bridges en route to its confluence with the North Branch at Wolf Point. At McClurg Court it passes the Nicholas J Melas Centennial Fountain, which was built in 1989 to celebrate the 100th anniversary of the Metropolitan Water Reclamation District of Greater Chicago; between May and October the fountain sends an arc of water over the river for ten minutes every hour.^[24] On the north bank of the river, near the Chicago Landmark Michigan Avenue Bridge, is Pioneer Court, which marks the site of the homestead of Jean Baptiste Point du Sable who is recognized as the founder of Chicago.^[25] On the south bank of the river is the site of Fort Dearborn. Notable buildings surrounding this area include the NBC Tower, the Tribune Tower, and the Wrigley Building. The river turns slightly to the south west between Michigan Avenue and State Street, passing the Trump International Hotel and Tower, 35 East Wacker, and 330 North Wabash. Turning west again the river passes Marina City, the Reid, Murdoch & Co. Building, and Merchandise Mart, and 333 Wacker Drive.

South Branch[link]

The confluence of the North Branch (upper right) and Main Stem (lower right) of the Chicago River at Wolf Point to form the South Branch of the Chicago River (left)

The source of the South Branch of the Chicago River is the confluence of the North Branch and Main stem at Wolf Point. From here the river flows south passing the Lake Street, Randolph Street, Washington Street, Madison Street, Monroe Street, Adams Street, Jackson Boulevard, Van Buren Street, Congress Parkway, and Harrison Street bridges before leaving the downtown Loop community area. Notable buildings that line this stretch of the river include the Boeing Company World Headquarters, the Civic Opera House, the Chicago Mercantile Exchange, Union Station and Willis Tower.

The river continues southwards past railroad yards. Between Polk and 18th Streets the river originally made a meander to the east; between 1927 and 1929 the river was straightened and moved ¹⁄₄ miles (0.40 km) west at this point to make room for a railroad terminal.^[26] The river turns to the south west at Ping Tom Memorial Park where it passes under the Chicago Landmark Canal Street railroad bridge. The river turns westward where it is crossed by the Dan Ryan Expressway; these immovable bridges have a clearance of 60 feet (18 m) requiring large ships that pass underneath to have folding masts.^[27]

At Ashland Avenue the river widens to form the U.S. Turning Basin, the west bank of which was the starting point of the Illinois and Michigan Canal.^[28] At the basin the river is joined by a tributary, the South Fork of the river, which is commonly given the nickname Bubbly Creek. A bridge used to span the South Fork at this point that was too low for boats to pass meaning that their cargo needed to be unloaded at the bridge, and the surrounding neighborhood became known as Bridgeport.^[29] The river continues to the south west, entering the Chicago Sanitary and Ship Canal at Damen Avenue. The original West Fork of the South Branch has been filled in; a triangular intrusion into the north bank at Damen Avenue marks the place where it diverged from the course of the canal.^[29] From the canal, the water flows into the Des Plaines River and eventually reaches the Gulf of Mexico.

Discharge[link]

The United States Geological Survey monitors water flow at a number of sites in the Chicago River system. Discharge from the North Branch is measured at Grand Avenue; between 2004 and 2010 this averaged 582 cubic feet (16.5 m³) per second.^[30] During the winter months as much as 75% of the flow in the North Branch is due to the discharge of treated sewage from the North Side Water Reclamation Plant into the North Shore Channel.^[31] Flow on the Main Stem is measured at Columbus Drive; between 2000 and 2006 this averaged 136 cubic feet (3.9 m³) per second.^[32]

History[link]

Early non-Native American settlers[link]

Near the mouth of the Chicago River 1831

Louis Jolliet and Jacques Marquette, though probably not the first Europeans to visit the area, are the first recorded to have visited the Chicago River in 1673, when they wrote of their discovery of the geographically vital Chicago Portage.^[33] Marquette returned in 1674, camped a few days near the mouth of the river, then moved on to the Chicago River–Des Plaines River portage, where he stayed through the winter of 1674–75. The Fox Wars effectively closed the Chicago area to Europeans in the first part of the 18th century. The first non-native to re-settle in the area may have been a trader named Guillory, who might have had a trading-post near Wolf Point on the Chicago River in around 1778.^[34] In 1823 a government expedition used the name Gary River (phonetic spelling of Guillory) to refer to the north branch of the Chicago River.

Jean Baptiste Point du Sable is widely regarded as the first permanent resident of Chicago; he built a farm on the northern bank at the mouth of the river in the 1780s.^[35] The earliest known record of Pointe du Sable living in Chicago is the diary of Hugh Heward, who made a journey through Illinois in the spring of 1790. Antoine Ouilmette claimed to have arrived in Chicago shortly after this in July 1790.^[36] In 1803, Fort Dearborn was constructed on the opposite bank on the site of the present-day Michigan Avenue Bridge.^[37] Lieutenant James Strode Swearingen, who led the troops from Detroit to Chicago to establish the fort, described the river as being about 30 yards (27 m) wide and upwards of 18 feet (5.5 m) deep at the place where the fort was intended to be built; the riverbanks were 8 feet (2.4 m) high on the south side and 6 feet (1.8 m) on the north.^[38]

Note the "Before" map above does not include the layout of the then existing Illinois and Michigan Canal (built 1848), which did not generally affect directional flow

Early improvements[link]

Between 1816 and 1828 soldiers from Fort Dearborn cut channels through the sandbar at the mouth of the river to allow yawls to bring supplies to the fort.^[39] These channels rapidly clogged with sand requiring a new one to be cut. On March 2, 1833 $25,000^{[n 1]} was appropriated by Congress for harbor works, and work began in June of that year under the supervision of Major George Bender, the commandant at Fort Dearborn.^[39][41] In January 1834 James Allen took over the supervision of this work^[42] and, aided by a February storm that breached the sandbar, on July 12, 1834 the harbor works had progressed enough to allow a 100-short-ton (91 t) schooner, the Illinois to sail up the river to Wolf Point and dock at the wharf of Newberry & Dole.^[39] The initial entrance through the sandbar was 200 feet (61 m) wide and 3 to 7 feet (0.91 to 2.1 m) deep, flanked by piers 200 feet (61 m) long on the south wall and 700 feet (210 m) long to the north. Allen's work continued, and by October 1837 the still unfinished piers had been extended to 1,850 feet (560 m) and 1,200 feet (370 m) respectively.^[43]

In 1848, the Illinois and Michigan canal linked the river to the Illinois River and the Mississippi Valley across the Chicago Portage.

In 1900, the river's flow was reversed in order to keep Lake Michigan clean.

Reversing the flow[link]

During the last ice age, the area that became Chicago was covered by Lake Chicago, which drained south into the Mississippi Valley. As the ice and water retreated, a short 12 to 14-foot (4.3 m) ridge was exposed about a mile inland which generally separated the Great Lake's watershed from the Mississippi Valley, except in times of heavy precipitation or when winter ice flows prevented drainage.^[44] By the time Europeans arrived, the Chicago River flowed sluggishly into Lake Michigan from Chicago's flat plain. As Chicago grew, this allowed sewage and other pollution into the clean-water source for the city, contributing to several public health problems, like typhoid fever.^[45] Starting in 1848, much of the Chicago River's flow was also diverted across the Chicago Portage into the Illinois and Michigan Canal.^[46] In 1871, the old canal was deepened in an attempt to completely reverse the river's flow but the reversal of the river only lasted one season.^[47]

Finally, in 1900, the Sanitary District of Chicago, then headed by William Boldenweck, completely reversed the flow of the Main Stem and South Branch of the river using a series of canal locks, increasing the river's flow from Lake Michigan and causing it to empty into the newly completed Chicago Sanitary and Ship Canal. In 1999, this system was named a 'Civil Engineering Monument of the Millennium' by the American Society of Civil Engineers (ASCE).^[48] Before this time, the Chicago River was known by many local residents of Chicago as "the stinking river" because of the massive amounts of sewage and pollution which poured into the river from Chicago's booming industrial economy. Through the 1980s, the river was quite dirty and often filled with garbage; however, during the 1990s, it underwent extensive cleaning as part of an effort at beautification by Chicago Mayor Richard M. Daley.

In 2005, researchers at the University of Illinois at Urbana-Champaign created a three-dimensional, hydrodynamic simulation of the Chicago River, which suggested that density currents are the cause of an observed bi-directional wintertime flow in the river. At the surface, the river flows east to west, away from Lake Michigan, as expected. But deep below, near the riverbed, water travels, seasonally, west to east, toward the lake.^[49]

All outflows from the Great Lakes Basin are regulated by the joint U.S.-Canadian Great Lakes Commission, and the outflow through the Chicago River is set under a U.S. Supreme Court decision (1967, modified 1980 and 1997). The city of Chicago is allowed to remove 3200 cubic feet per second (91 m³/s) of water from the Great Lakes system; about half of this, 1 billion US gallons a day (44 m³/s), is sent down the Chicago River, while the rest is used for drinking water.^[50] In late 2005, the Chicago-based Alliance for the Great Lakes proposed re-separating the Great Lakes and Mississippi River basins to address such ecological concerns as the spread of invasive species.^[51]

Eastland disaster[link]

Passengers being rescued from the hull of the Eastland by the tugboat Kenosha in the Chicago River

In 1915, the Eastland, an excursion boat docked at the Clark Street bridge, rolled over, killing 844 passengers.^[52] Many of the passengers were trapped by moving objects such as pianos and tables. The site is now the location of a memorial which was dedicated in 1989. The marker was stolen in 2000 and replaced in 2003. There are plans to build an outdoor exhibit at the site as well.

Chicago Flood[link]

On April 13, 1992, the Chicago Flood occurred when a pile driven into the riverbed caused stress fractures in the wall of a long-abandoned tunnel of the Chicago Tunnel Company near the Kinzie Street railroad bridge. Most of the 60-mile (97 km) network of underground freight railway, which encompasses much of downtown, was eventually flooded, along with the lower levels of buildings it once serviced and attached underground shops and pedestrian ways.

Bridges[link]

State Street Bridge raised to allow boats to pass

The Link Bridge of Lake Shore Drive

The first bridge across the Chicago River was constructed over the north branch near the present day Kinzie Street in 1832. A second bridge, over the south branch near Randolph Street, was added in 1833.^[53] The first moveable bridge was constructed across the main stem at Dearborn Street in 1834.^[54] Today, the Chicago River has 38 movable bridges spanning it, down from a peak of 52 bridges.^[55] These bridges are of several different types, including trunnion bascule, scherzer rolling lift, swing bridges, and vertical lift bridges.

Pollution[link]

The Chicago River has been highly affected by industrial and residential development with attendant changes to the quality of the water and riverbanks. Several species of freshwater fish are known to inhabit the river, including largemouth and smallmouth bass, rock bass, crappie, bluegill, catfish, and carp. The river also has a large population of crayfish. The South Fork of the Main (South) Branch, which was the primary sewer for the Union Stock Yards and the meat packing industry, was once so polluted that it became known as Bubbly Creek.^[56] Illinois has issued advisories regarding eating fish from the river due to PCB and mercury contamination, including a "do not eat" advisory for carp more than 12 inches long.^[57] There are concerns that silver carp and bighead carp, now invasive species in the Mississippi and Illinois Rivers, may reach the Great Lakes through the Chicago River.^[58] Despite the pollution concerns, the Chicago River remains a very popular target for freshwater recreational fishing. In 2006, the Chicago Park District started the annual "Mayor Daley's Chicago River Fishing Festival", which has increased in popularity with each year.

Near the mouth of the Chicago River 1893   Near the mouth of the Chicago River circa late 1800s   Near the mouth of the Chicago River 1838

St. Patrick's Day[link]

The Chicago River during the 2009 Saint Patrick's Day celebration.

As part of a more than forty year old Chicago tradition, the Chicago River is dyed green in observance of St. Patrick's Day.^[59] The actual event does not necessarily occur on St. Patrick's Day and is scheduled for the Saturday of the closest weekend. The dye takes days to dissipate.

The tradition of dyeing the river green arose by accident when some plumbers used fluorescein dye to trace sources of illegal pollution discharges.^[60] The dyeing of the river is still sponsored by the local plumbers union.^[61]

The United States Environmental Protection Agency (EPA) outlawed the use of fluorescein for this purpose, since it was shown to be harmful to the river.^[60] The present ingredients used to dye the river green today are safe for people and wildlife.^[60] Forty pounds of powdered vegetable dye are used to color the river for the celebration.^[62]

In 2009, in keeping with the Chicago St. Patrick's Day tradition, at the request of Chicago native First Lady Michelle Obama, the White House fountains were dyed green to celebrate St. Patrick's Day.^[63]

See also[link]

• Centennial Fountain
• Chicago's First Lady
• Illinois Department of Transportation
• List of rivers of Illinois

Notes and references[link]

Notes

References

Bibliography

External links[link]

Wikimedia Commons has media related to: Chicago River

• Friends of the Chicago River
• GreenChicagoRiver.com
• Metropolitan Water Reclamation District of Greater Chicago

News

• "Feds order cleanup of Chicago River". Chicago Tribune (Associated Press). 12 May 2011. http://www.chicagotribune.com/news/chi-ap-il-chicagoriver-clea,0,5578814.story. 

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Coordinates: 41°53′11″N 87°38′15″W / 41.88639°N 87.6375°W / 41.88639; -87.6375

Chicago
—  City  —
Clockwise from top: Downtown Chicago, the Chicago Theatre, the Chicago 'L', Navy Pier, Millennium Park, the Field Museum, and the Willis (formerly Sears) Tower
Flag Seal
Nickname(s): The Windy City, The Second City, Chi-Town, Hog Butcher for the World, City of Big Shoulders, The City That Works, White City, and others found at List of nicknames for Chicago
Motto: Latin: Urbs in Horto (City in a Garden), Make Big Plans (Make No Small Plans), I Will
Location in the Chicago metropolitan area and Illinois
Chicago Location in the United States
Coordinates: 41°52′55″N 87°37′40″W / 41.88194°N 87.62778°W / 41.88194; -87.62778Coordinates: 41°52′55″N 87°37′40″W / 41.88194°N 87.62778°W / 41.88194; -87.62778
Country	United States
State	Illinois
Counties	Cook, DuPage
Settled	1770s
Incorporated	March 4, 1837
Named for	Miami-Illinois: shikaakwa ("Wild onion")
Government
• Type	Mayor–council
• Mayor	Rahm Emanuel (D)
• City Council
Area
• City	234.0 sq mi (606.1 km2)
• Land	227.2 sq mi (588 km2)
• Water	6.9 sq mi (18 km2)  3.0%
• Urban	2,122.8 sq mi (5,498 km2)
• Metro	10,874 sq mi (28,160 km2)
Elevation	597 ft (182 m)
Population (2010 Census)[1][2]
• City	2,695,598
• Rank	3rd US
• Density	11,864.4/sq mi (4,447.4/km2)
• Urban	8,711,000
• Metro	9,461,105
Demonym	Chicagoan
Time zone	CST (UTC−06:00)
• Summer (DST)	CDT (UTC−05:00)
Area code(s)	312, 773, 872
Website	cityofchicago.org
[3]

Chicago (ⁱ/ʃɪˈkɑːɡoʊ/ or /ʃɪˈkɔːɡoʊ/) is the largest city in the US state of Illinois and the third most populous city in the United States after New York City and Los Angeles. The city has around 2.7 million residents.^[1] Its metropolitan area, sometimes called "Chicagoland", is the third largest in the United States,^[4][5][6] with an estimated 9.8 million people. Chicago is the county seat of Cook County,^[7] though a small portion also extends into DuPage County.

Chicago was incorporated as a city in 1837, near a portage between the Great Lakes and the Mississippi River watershed.^[8] Today, Chicago is listed as an alpha+ global city by the Globalization and World Cities Research Network, and ranks seventh in the world on the 2012 Global Cities Index. The city retains its status as an international hub for finance, industry, telecommunications and infrastructure, with O'Hare International Airport being the second busiest airport in the world in terms of traffic movements. In 2008^[update], the city hosted 45.6 million domestic and overseas visitors.^[9] Among metropolitan areas, Chicago has the 4th largest Gross Domestic Product (GDP) in the world, ranking just behind Tokyo, New York City, and Los Angeles.^[10] Chicago is one of the most important Worldwide Centers of Commerce and trade.

Chicago's notoriety has found expression in numerous forms of popular culture, including novels, plays, movies, songs, various types of journals (for example, sports, entertainment, business, trade, and academic), and the news media. The city has many nicknames, which reflect the impressions and opinions about historical and contemporary Chicago. The best known include: "Chi-town", "Windy City," "Second City,"^{[n 1]} and the "City of the Big Shoulders."^{[n 2]}

History[link]

During the mid-18th century, the area was inhabited by a Native American tribe known as the Potawatomi, who had taken the place of the Miami and Sauk and Fox peoples. The 1780s saw the arrival of the first known non-indigenous permanent settler in Chicago, Jean Baptiste Point du Sable, who is believed to be of Haitian and French descent.^[12] In 1795, following the Northwest Indian War, an area that was to be part of Chicago was turned over by some Native Americans in the Treaty of Greenville to the United States for a military post.

In 1803, the United States Army built Fort Dearborn, which was destroyed in the War of 1812, Battle of Fort Dearborn. The Ottawa, Ojibwe, and Potawatomi tribes had ceded additional land to the United States in the 1804 Treaty of St. Louis. The Potawatomi were eventually forcibly removed from their land following the Treaty of Chicago in 1833. On August 12, 1833, the Town of Chicago was organized with a population of around 200 at that time.^[13] Within seven years it would grow to a population of over 4,000. On the 15th day of June, 1835, the first public land sales commenced with Edmund Dick Taylor as U.S. receiver of public moneys. The City of Chicago was incorporated on Saturday, March 4, 1837.

The name "Chicago" is derived from a French rendering of the Native American word shikaakwa, translated as "wild onion" or "wild garlic," from the Miami-Illinois language.^{[14][15][16][17]} The first known reference to the site of the current city of Chicago as "Checagou" was by Robert de LaSalle around 1679 in a memoir written about the time.^[18] The wild garlic plants, Allium tricoccum, were described by LaSalle's comrade, naturalist-diarist Henri Joutel, in his journal of LaSalle's last expedition.^[19][20]

State and Madison Streets, the busiest corner in Chicago (1897)

As the site of the Chicago Portage, the city emerged as an important transportation hub between the eastern and western United States. Chicago's first railway, Galena and Chicago Union Railroad, opened in 1848, which also marked the opening of the Illinois and Michigan Canal. The canal allowed steamboats and sailing ships on the Great Lakes to connect to the Mississippi River. A flourishing economy brought residents from rural communities and immigrants abroad. Manufacturing and retail sectors became dominant among Midwestern cities, influencing the American economy, particularly in meatpacking, with the advent of the refrigerated rail car and the regional centrality of the city's Union Stock Yards.^[21]

In the 1850s Chicago gained national political prominence as the home of Senator Stephen Douglas, the champion of the Kansas-Nebraska Act and "popular sovereignty" approach to the issue of the spread of slavery.^[22] These issues also helped propel another Illinoisan, Abraham Lincoln, to the national stage. Lincoln was nominated in Chicago for the nation's presidency at the 1860 Republican National Convention and went on to defeat Douglas in the general election, setting the stage for the American Civil War.

To accommodate rapid population growth and demand for better sanitation, the city implemented various infrastructural improvements. In February 1856, the Chesbrough plan for the building of the United States' first comprehensive sewerage system was approved by the Common Council.^[23] The project raised much of central Chicago to a new grade. While raising Chicago, and at first improving the health of the city, the untreated sewage and industrial waste now flowed into the Chicago River, then into Lake Michigan, polluting the primary source of fresh water for the city. The city responded by tunneling two miles (3 km) out into Lake Michigan to newly built water cribs. In 1900, the problem of sewage contamination was largely resolved when the city reversed the flow of the Chicago River so that it flowed away from Lake Michigan, rather than into it. This project began with the construction and improvement of the Illinois and Michigan Canal, and was completed with the Chicago Sanitary and Ship Canal that connects to the Illinois River, which flows into the Mississippi River.

Artist's rendering of the Great Chicago Fire of 1871

In 1871, the Great Chicago Fire broke out, destroying an area of about 4 miles long and 1 mile wide, a large section of the city at the time. Much of the city, including railroads and stockyards, survived intact, and from the ruins of the previous wooden structures arose more modern constructions of steel and stone which would set the precedent for worldwide construction.^[24] During its rebuilding period, Chicago constructed the world's first skyscraper in 1885, using steel-skeleton construction.^[25] Labor conflicts and unrest followed, including the Haymarket affair on May 4, 1886. Concern for social problems among Chicago's lower classes led Jane Addams to be a co-founder of Hull House in 1889. Programs developed there became a model for the new field of social work.

During the 1870s and 1880s, Chicago attained national stature as the leader in the movement to improve public health. City, and later state laws, that upgraded standards for the medical profession and fought urban epidemics of cholera, small pox, and yellow fever were not only passed, but also enforced. These in turn became templates for public health reform in many other cities and states.^[26] The city invested in many large, well-landscaped municipal parks, which also included public sanitation facilities. The chief advocate and driving force for improving public health in Chicago was Dr. John H. Rauch, M.D., who established a plan for Chicago's park system in 1866, created Lincoln Park by closing a cemetery filled with festering, shallow graves, and helped establish a new Chicago Board of Health in 1867 in response to an outbreak of cholera. Ten years later he became the secretary and then the president of the first Illinois State Board of Health, which carried out most of its activities in Chicago.^[27]

In the 19th century, Chicago became the nation's railroad center, a title it still holds. In 1883, the standardized system of North American Time Zones was adopted by the general time convention of railway managers in Chicago.^[28] This gave the continent its uniform system for telling time.

In 1893, Chicago hosted the World's Columbian Exposition on former marshland at the present location of Jackson Park. The Exposition drew 27.5 million visitors, and is considered the most influential world's fair in history.^[29] The University of Chicago was founded in 1892 on the same South Side location. The term "midway" for a fair or carnival referred originally to the Midway Plaisance, a strip of park land that still runs through the University of Chicago campus and connects Washington and Jackson Parks.

Men outside a soup kitchen in Chicago during the Great Depression (1931)

Chicago's flourishing economy attracted huge numbers of new immigrants from Europe and migrants from the eastern states. Of the total population in 1900 not less than 77% were foreign-born, or born in the United States of foreign parentage. Germans, Irish, Poles, Swedes and Czechs made up nearly two-thirds of the foreign-born population.^[30] In 1900, whites were 98.1% of the city's population.^[31]

20th and 21st centuries[link]

The 1920s saw gangsters, including Al Capone, battle law enforcement and each other on the streets of Chicago during the Prohibition era.^[32] In 1924, Chicago was the first American city to have a homosexual-rights organization, the Society for Human Rights. This organization produced the first American publication for gays, Friendship and Freedom.

The Chicago River is the south border (right) of the Near North Side and Streeterville and the north border (left) of Chicago Loop, Lakeshore East and Illinois Center (from Lake Shore Drive's Link Bridge with Trump International Hotel and Tower at jog in the river in the center)

The 1920s also saw a major expansion in industry. The availability of jobs attracted blacks from the South. Between 1910 and 1930, the black population of Chicago dramatically increased from 44,103 to 233,903.^[33] Arriving in the hundreds of thousands during the Great Migration, the newcomers had an immense cultural impact. It was during this wave that Chicago became a center for jazz, with King Oliver leading the way.^[34]

In 1933, Chicago Mayor Anton Cermak was fatally wounded in Miami, Florida during a failed assassination attempt on President-elect Franklin D. Roosevelt. In 1933 and 1934, the city celebrated its centennial by hosting the Century of Progress International Exposition Worlds Fair.^[35] The theme of the fair was technological innovation over the century since Chicago's founding.^[36]

On December 2, 1942, physicist Enrico Fermi conducted the world's first controlled nuclear reaction at Chicago's University of Chicago as part of the top-secret Manhattan Project. This led to the creation of the atomic bomb by the United States, which it used in World War II in 1945.

Downtown Chicago as seen from the Willis Tower Skydeck

Mayor Richard J. Daley was elected in 1955, in the era of machine politics. Starting in the early 1960s due to blockbusting, many white residents, as in most American cities, left the city for the suburbs. Whole neighborhoods were completely changed based on race. Structural changes in industry caused heavy losses of jobs for lower skilled workers. In 1966, James Bevel, Martin Luther King, Jr., and Albert Raby led the Chicago Open Housing Movement, which culminated in agreements between Mayor Richard J. Daley and the movement leaders. Two years later, the city hosted the tumultuous 1968 Democratic National Convention, which featured physical confrontations both inside and outside the convention hall, including full-scale riots, or in some cases police riots, in city streets. Major construction projects, including the Sears Tower (now known as the Willis Tower, which in 1974 became the world's tallest building), University of Illinois at Chicago, McCormick Place, and O'Hare International Airport, were undertaken during Richard J. Daley's tenure. When Richard J. Daley died, Michael Anthony Bilandic served as mayor for three years. Bilandic's subsequent loss in a primary election has been attributed to the city's inability to properly plow city streets during a heavy snowstorm. In 1979, Jane Byrne, the city's first female mayor, was elected. She popularized the city further as a movie location and tourist destination.

In 1983, Harold Washington became the first African American to be elected to the office of mayor, in one of the closest mayoral elections in Chicago. After Washington won the Democratic primary, racial motivations caused a few Democratic alderman and ward committeemen to back the Republican candidate Bernard Epton, who ran on the race-baiting slogan Before it's too late.^[37] Washington's term in office saw new attention given to poor and minority neighborhoods. Washington died in office of a heart attack in 1987, shortly after being elected to a second term. The balance of Washington's second term was served by 6th ward Alderman Eugene Sawyer. Richard M. Daley, son of Richard J. Daley, was elected in 1989. His accomplishments included improvements to parks and creating incentives for sustainable development. After successfully standing for reelection five times and becoming Chicago's longest serving Mayor, Richard M. Daley announced he would step down at the end of his final term in 2011.

On February 23, 2011, former White House chief of staff and congressman Rahm Emanuel won the municipal election to succeed Daley, beating five rivals with 55 percent of the vote. The other five candidates split the remaining 45 percent of votes.^[38] Emanuel was sworn in as Mayor on May 16, 2011.

Geography[link]

Topography[link]

Aerial view of the Loop and the North Side with beaches lining the waterfront.

Chicago is located in northeastern Illinois at the southwestern tip of Lake Michigan. It is the principal city in Chicago Metropolitan Area situated in the Midwestern United States and the Great Lakes region. Chicago rests on a continental divide at the site of the Chicago Portage, connecting the Mississippi River and the Great Lakes watersheds. The city lies beside freshwater Lake Michigan, and two rivers— the Chicago River in downtown and the Calumet River in the industrial far South Side – flow entirely or partially through Chicago. The Chicago Sanitary and Ship Canal connects the Chicago River with the Des Plaines River, which runs to the west of the city. Chicago's history and economy are closely tied to its proximity to Lake Michigan. While the Chicago River historically handled much of the region's waterborne cargo, today's huge lake freighters use the city's Lake Calumet Harbor on the South Side. The lake also provides another positive effect, moderating Chicago's climate; making waterfront neighborhoods slightly warmer in winter and cooler in summer.

When Chicago was founded in 1833, most of the early building began around the mouth of the Chicago River, as can be seen on a map of the city's original 58 blocks.^[39] The overall grade of the city's central, built-up areas, is relatively consistent with the natural flatness of its overall natural geography, generally exhibiting only slight differentiation otherwise. The average land elevation is 579 ft (176 m) above sea level. The lowest points are along the lake shore at 577 ft (176 m), while the highest point, at 735 ft (224 m), is a landfill located in the Hegewisch community area on the city's far south side.

Chicago Half Marathon on Lake Shore Drive next to Burnham Park in the South Side

The Chicago Loop is the central business district, but Chicago is also a city of neighborhoods. Lake Shore Drive runs adjacent to a large portion of Chicago's lakefront. Some of the parks along the waterfront include Lincoln Park, Grant Park, Burnham Park and Jackson Park. 29 public beaches are also found along the shore. Landfill extends into portions of the lake providing space for Navy Pier, Northerly Island, the Museum Campus, and large portions of the McCormick Place Convention Center. Most of the city's high-rise commercial and residential buildings can be found close to the waterfront.

An informal name for the Chicago metropolitan area is Chicagoland, used primarily by copywriters, advertising agencies, and traffic reporters. There is no precise definition for the term "Chicagoland," but it generally means the city and its suburbs together. The Chicago Tribune, which coined the term, includes the city of Chicago, the rest of Cook County, eight nearby Illinois counties: Lake, McHenry, DuPage, Kane, Kendall, Grundy, Will and Kankakee, and three counties in Indiana: Lake, Porter and LaPorte.^[40] The Illinois Department of Tourism defines Chicagoland as Cook County without the city of Chicago, and only Lake, DuPage, Kane and Will counties.^[41] The Chicagoland Chamber of Commerce defines it as all of Cook and DuPage, Kane, Lake, McHenry and Will counties.^[42]

Chicago Harbor Lighthouse

Climate[link]

The city lies within the humid continental climate zone, and experiences four distinct seasons. Summers are hot and humid, with a July daily average of 84.7 °F (29.3 °C). In a normal summer, temperatures exceed 90 °F (32 °C) on 21 days.^[43] Winters are cold, snowy, and windy, with some sunny days, and with a January average of 23.5 °F (−4.7 °C). Temperatures often (43 days) stay below freezing for an entire day, and lows below 0 °F (−18 °C) occur on eight nights per year.^[43] Spring and fall are mild seasons with low humidity.

According to the National Weather Service, Chicago's highest official temperature reading of 107 °F (42 °C) was recorded on June 1, 1934, and July 11, 1936, both at Midway Airport. The lowest temperature of −27 °F (−33 °C) was recorded on January 20, 1985,^[43] at O'Hare Airport. The city can experience extreme winter cold waves and summer heat waves that may last for several consecutive days. Severe weather is also common in the Chicago area, such as the F4 tornado that devastated the south side of the city on April 21, 1967. As well as the F-5 that ravaged some of the Southwest suburbs on August 28, 1990

Cityscape[link]

Chicago skyline April 18, 2009, from Northerly Island looking west.

Chicago August 9, 2010, from John Hancock Center looking south.

Architecture[link]

The outcome of the Great Chicago Fire led to the largest building boom in the history of the nation. In 1885, the first steel-framed high-rise building, the Home Insurance Building, rose in the city as Chicago ushered in the skyscraper era, which would then be followed by many other cities around the world.^[47] Today, Chicago's skyline is among the world's tallest and most dense.^[48] The United States' two tallest towers are both located in Chicago; Willis Tower (formerly Sears Tower, and the tallest building in the Western Hemisphere), and Trump International Hotel and Tower. The Loop's historic buildings include the Chicago Board of Trade Building, the Fine Arts Building, 35 East Wacker, and the Chicago Building, 860-880 Lake Shore Drive Apartments by Mies van der Rohe. Many other architects have left their impression on the Chicago skyline such as Daniel Burnham, Louis Sullivan, Charles B. Atwood, John Root, and Helmut Jahn. The Merchandise Mart, once first on the list of largest buildings in the world, and still listed as 20th, has its own ZIP code, and stands near the junction of the North and South branches of the Chicago River. Presently, the four tallest buildings in the city are Willis Tower (formerly the Sears Tower, also a building with its own zip code), Trump International Hotel and Tower, the Aon Center (previously the Standard Oil Building), and the John Hancock Center. Industrial districts, such as some areas on the South Side, the areas along the Chicago Sanitary and Ship Canal, and Northwest Indiana are clustered.

Chicago gave its name to the Chicago School and was home to the Prairie School, movements in architecture. Multiple kinds and scales of houses, townhouses, condominiums, and apartment buildings can be found in Chicago. Large swaths of Chicago's residential areas away from the lake are characterized by brick bungalows built from the early 20th century through the end of World War II. Chicago is also a prominent center of the Polish Cathedral style of church architecture. The Chicago suburb of Oak Park was home to famous architect Frank Lloyd Wright, who had designed The Robie House located near the University of Chicago as well as many prominent buildings across the country.

Unlike many Midwestern and East Coast cities, Chicago tends to have wider streets. A positive effect of this is that it alleviates the feeling of being engulfed by the city's large skyscrapers. Most of the city's residential streets also tend to have a wide patch of grass and/or trees located between the street and the sidewalk itself. This has the effect of keeping pedestrians walking on the sidewalk further away from the street traffic. Chicago's Western Avenue is the longest continuous urban street in the world. Other famous streets include North Michigan Avenue, North State Street, Clark, and Belmont Avenue. The City Beautiful movement inspired Chicago's boulevards and parkways.

Culture and contemporary life[link]