San Francisco the time. San Francisco became a consolidated city-county in 1856. San Francisco's status as the West Coast's largest city peaked between 1870 and 1900, when around 25% of California's population resided in the city proper. After three-quarters of the city was destroyed by the 1906 earthquake and fire, San Francisco was quickly rebuilt, hosting the Panama-Pacific International Exposition nine years later. In World War II, San Francisco was a major port of embarkation for service members shipping out to the Pacific Theater. It then became the birthplace of the United Nations in 1945. After the war, the confluence of returning
San Francisco International Airport shift all of their service from the airport to Oakland and San Jose. However, Southwest eventually returned to SFO in 2007. A long-planned extension of the Bay Area Rapid Transit (BART) system to the airport opened on June 22, 2003, allowing passengers to board BART trains at the international or domestic terminals and have direct rail transportation to downtown San Francisco, Oakland, and the East Bay. On February 24, 2003, the AirTrain people mover opened, transporting passengers between terminals, parking lots, the BART station, and the rental car center on small automatic trains. SFO became the base of operations for