1840s

The 1840s decade ran from January 1, 1840, to December 31, 1849.

Politics and wars

Pacific Islands

In 1842, Tahiti and Tahuata were declared a French protectorate, to allow Catholic missionaries to work undisturbed. The capital of Papeetē was founded in 1843. In 1845, George Tupou I united Tonga into a kingdom, and reigned as Tuʻi Kanokupolu.

East Asia

China

On August 29, 1842, the first of two Opium Wars ended between China and Britain with the Treaty of Nanking. One of the consequences was the cession of modern-day Hong Kong Island to the British. Hong Kong would eventually be returned to China in 1997.

Other events:

United States

Coordinates: 40°N 100°W / 40°N 100°W / 40; -100

The United States of America (USA), commonly referred to as the United States (U.S.) or America, is a federal republic composed of 50 states, a federal district, five major territories and various possessions. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is in the northwestern part of North America and the state of Hawaii is an archipelago in the mid-Pacific. The territories are scattered about the Pacific Ocean and the Caribbean Sea. At 3.8 million square miles (9.842 million km²) and with over 320 million people, the country is the world's third or fourth-largest by total area and the third most populous. It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The geography and climate of the United States are also extremely diverse, and the country is home to a wide variety of wildlife.

New York

New York is a state in the Northeastern United States and is the United States' 27th-most extensive, fourth-most populous, and seventh-most densely populated state. New York is bordered by New Jersey and Pennsylvania to the south and Connecticut, Massachusetts, and Vermont to the east. The state has a maritime border in the Atlantic Ocean with Rhode Island, east of Long Island, as well as an international border with the Canadian provinces of Quebec to the north and Ontario to the west and north. The state of New York, with an estimated 19.8 million residents in 2015, is often referred to as New York State to distinguish it from New York City, the state's most populous city and its economic hub.

With an estimated population of nearly 8.5 million in 2014, New York City is the most populous city in the United States and the premier gateway for legal immigration to the United States. The New York City Metropolitan Area is one of the most populous urban agglomerations in the world. New York City is a global city, exerting a significant impact upon commerce, finance, media, art, fashion, research, technology, education, and entertainment, its fast pace defining the term New York minute. The home of the United Nations Headquarters, New York City is an important center for international diplomacy and has been described as the cultural and financial capital of the world, as well as the world's most economically powerful city. New York City makes up over 40% of the population of New York State. Two-thirds of the state's population lives in the New York City Metropolitan Area, and nearly 40% live on Long Island. Both the state and New York City were named for the 17th century Duke of York, future King James II of England. The next four most populous cities in the state are Buffalo, Rochester, Yonkers, and Syracuse, while the state capital is Albany.

Library of Congress

The Library of Congress is the research library that officially serves the United States Congress, but which is the de facto national library of the United States. It is the oldest federal cultural institution in the United States. The Library is housed in three buildings on Capitol Hill in Washington, D.C., and also maintains the Packard Campus in Culpeper, Virginia, which houses the National Audio-Visual Conservation Center.

The library is the second largest library by collection size, with the largest being the British Library. The Library's "collections are universal, not limited by subject, format, or national boundary, and include research materials from all parts of the world and in more than 450 languages. Two-thirds of the books it acquires each year are in languages other than English."

The Library of Congress moved to Washington in 1800, after sitting for eleven years in the temporary national capitals of New York and Philadelphia. John J. Beckley, who became the first Librarian of Congress, was paid two dollars per day and was also required to serve as the Clerk of the House of Representatives. The small Congressional Library was housed in the United States Capitol for most of the 19th century until the early 1890s. Most of the original collection had been destroyed by the British in 1814 during the War of 1812. To restore its collection in 1815, the library bought from former president Thomas Jefferson his entire personal collection of 6,487 books.