Los Angeles (L.A.), officially the City of Los Angeles, is the largest city in California, in the United States. There are many ethnicities of people living in the city, and over 18 million people in the L.A. region. The city has an area of 1,200 square kilometres (460 sq mi). Los Angeles is the city with the second biggest population in the United States after New York, overtaking Chicago in the 1970s.