Key West City is the southernmost city of the continental United States. It is a port of entry and a cruise-ship stop, a popular resort with a tropical climate, a shrimping and fishing center, and an artists' colony. Tropical fruits are harvested, but tourism is central to the economy.

Early Spanish sailors called the site Cayo Hueso (Bone Island), because of the human bones they found there. A railroad (completed 1912) linked the Keys with the mainland. It was abandoned after being damaged by a hurricane in 1935 and was replaced by the 123-mi (198-km) Overseas Highway (completed in 1938). After a severe economic decline, the federal government took over (1934) the bankrupt city.

Places of interest include a sponge pier, an aquarium, a lighthouse (1846; replacing one built in 1825), Mallory Square (a daily sunset-viewing point), and two Civil War forts. John James Audubon and Winslow Homer painted in Key West, and the city was used as a setting in the works of Ernest Hemingway, who once lived there. His home (built 1851) was made a museum, as was the Little White House, President Harry S. Truman's personal retreat.