San Francisco is the commercial, financial, and cultural centre of Northern California. The city proper is the fourth most populous city in California, with 808,437 residents, and the 17th most populous city in the United States as of 2022. The city covers a land area of 46.9 square miles (121 square kilometers) at the end of the San Francisco Peninsula, making it the second-most densely populated large U.S. city after New York City. Prior to European settlement, the modern city proper was inhabited by the Yelamu, who spoke a language now referred to as Ramaytush Ohlone. On June 29, 1776, settlers from New Spain established the Presidio of San Francisco at the Golden Gate, and the Mission San Francisco de Asís a few miles away, both named for Francis of Assisi. The California Gold Rush of 1849 brought rapid growth, transforming an unimportant hamlet into a busy port, making it the largest city on the West Coast at the time; between 1870 and 1900, approximately one quarter of California's population resided in the city proper. In 1856, San Francisco became a consolidated city-county. After three-quarters of the city was destroyed by the 1906 earthquake and fire, it was quickly rebuilt, hosting the Panama-Pacific International Exposition nine years later. In World War II, it was a major port of embarkation for naval service members shipping out to the Pacific Theatre. In 1945, the United Nations Charter was signed in San Francisco, establishing the United Nations before permanently relocating to Manhattan, and in 1951, the Treaty of San Francisco re-established peaceful relations between Japan and the Allied Powers. After the war, the confluence of returning servicemen, significant immigration, liberalizing attitudes, the rise of the beatnik and hippie countercultures, the sexual revolution, the peace movement growing from opposition to United States involvement in the Vietnam War, and other factors led to the Summer of Love and the gay rights movement, cementing San Francisco as a centre of liberal activism in the United States.
