Los Angeles is the largest city in the U.S. state of California, and the second largest city in the United States (after New York City). It is the county seat of Los Angeles County in Southern California, in between the Pacific Ocean and the San Gabriel Mountains. It was founded by Spanish settlers in the 18th century. It was annexed by the United States after the Mexican-American War. It was smaller in population than San Francisco until the early 20th century. It has since experienced rapid growth and is now home to more than 3 million people. The economy of the city is diversified, with a major petroleum industry as well as the Hollywood movie industry. It is home to the U.S. Bank Tower, the tallest building on the West Coast. It is the anchor city of the Los Angeles metropolitan area and the Greater Los Angeles Area. It is served by the Los Angeles International Airport and Interstate 5.