Key West is a city and an island of the same name, the county seat of Monroe County, and an island in the Florida Keys. It is considered the southernmost city in the continental United States. In Pre-Columbian times Key West was inhabited by the Tequesta and Calusa peoples. The first European to visit was Juan Ponce de León in 1521. As Florida became a Spanish colony, a fishing and salvage village with a small garrison was established here. The island was used by fishermen from Cuba and from the British Bahamas, who were later joined by others from the United States after the latter nation's independence. While claimed by Spain, no nation exercised de facto control over the community there for some time. The island was considered the Gibraltar of the West because of its strategic location on the 90-mile (140 km)–wide deep shipping lane, the Straits of Florida, between the Atlantic Ocean and the Gulf of Mexico. On March 25, 1822, Matthew C. Perry sailed the schooner Shark to Key West and planted the U.S. flag, physically claiming the Keys as United States property. Key West was relatively isolated until 1912, when it was connected to the Florida mainland via the Overseas Railway extension of Henry M. Flagler's Florida East Coast Railway (FEC). The Labor Day Hurricane of 1935 destroyed much of the railroad and killed hundreds of residents. The FEC could not afford to restore the railroad. The U.S. government then rebuilt the rail route as an automobile highway, completed in 1938, which became an extension of United States Highway 1. The portion of U.S. 1 through the Keys is called the Overseas Highway. Key West claims to be the only city in the lower 48 states never to have had a frost. Because of the proximity of the Gulf Stream in the Straits of Florida, about 12 miles (19 km) south and southeast, and the tempering effects of the Gulf of Mexico to the west and north, Key West has a notably mild, tropical climate. Precipitation is characterized by dry and wet seasons. The period of November through Apri