The Great Lakes Patrol was carried out by American naval forces, beginning in 1844, mainly to suppress criminal activity and to protect the maritime border with Canada. Only a small force of United States Navy, Coast Guard, and Revenue Service ships served in the Great Lakes throughout the operations, though they were involved in several incidents with pirates and rebels. The patrol ended in 1920 when the Coast Guard assumed full command of the operations as part of the Rum Patrol.

The USS Michigan led the patrol, mostly singlehandedly, from its beginning on October 1, 1844 until the ship was retired in 1912. Michigan was the only American gunboat to patrol the huge Great Lakes and she was the navy's first steam powered, iron hulled, warship. The Michigan was built to defend the lakes due to the construction of two British steamers during the Canadian rebellions in 1837. Based out of Erie, Pennsylvania throughout her career, the gunboat was commissioned on September 29, 1844 under Commander William Inman. Because the Great Lakes are vast inland seas in the north of the continent, during every winter parts of the lakes would freeze over or icebergs would make navigation extremely hazardous and difficult. The Michigan usually sailed from about March to December before heading back for Erie for the winter where a type of house was built to protect the ship from the elements. The officers and crew of the ship either stayed at their homes in Erie or at a government owned hotel near the wharf.

The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada–United States border which connect to the Atlantic Ocean through the Saint Lawrence Seaway and the Great Lakes Waterway. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth comprising 21% of the world's surface fresh water. The total surface is 94,250 square miles (244,106 km²), and the total volume (measured at the low water datum) is 5,439 cubic miles (22,671 km³). The lakes are sometimes referred to as the North Coast or "Third Coast" by some citizens of the United States.

The lakes have been a major source of trade through this area, and they are home to a large number of aquatic species. Many invasive species have been introduced due to trade in the area, and some threaten the biodiversity of the area.

Though the five lakes reside in separate basins, they form a single, naturally interconnected body of fresh water. The lakes form a chain connecting the east-central interior of North America to the Atlantic Ocean. From the interior to the outlet at the St. Lawrence River, water flows from Superior to Michigan-Huron (in the hydrological sense, a single body of water), southward to Erie, and finally northward to Lake Ontario. The lakes drain a large watershed via many rivers, and are studded with approximately 35,000 islands. The Great Lakes region contains not only the five themselves but also many thousands of smaller lakes, often called inland lakes. Of the five lakes, Lake Michigan is the only one that is located entirely within the United States; the others form a water border between the United States and Canada.