Claim: Los Angeles, California is nicknamed the "City of Angels."

Los Angeles -LRB- -LSB- lɒs_ˈændʒəlᵻs -RSB- , Spanish for `` The Angels '' ; -LSB- los ˈaŋxeles -RSB- -RRB- , officially the City of Los Angeles and often known by its initials L.A. , is the cultural , financial , and commercial center of Southern California . With a census-estimated 2017 population of 4,042,000 , it is the second-most populous city in the United States -LRB- after New York City -RRB- and the most populous city in the state of California . Located in a large coastal basin surrounded on three sides by mountains reaching up to and over 10000 ft , Los Angeles covers an area of about 469 sqmi . The city is also the seat of Los Angeles County , the most populated county in the country . Los Angeles is the center of the Los Angeles metropolitan area , and is part of the larger designated Los Angeles-Long Beach combined statistical area -LRB- CSA -RRB- , the second most populous in the nation with a 2015 estimated population of 18.7 million .   Historically home to the Chumash and Tongva , Los Angeles was claimed by Juan Rodríguez Cabrillo for Spain in 1542 along with the rest of what would become Alta California . The city was officially founded on September 4 , 1781 , by Spanish governor Felipe de Neve . It became a part of Mexico in 1821 following the Mexican War of Independence . In 1848 , at the end of the Mexican -- American War , Los Angeles and the rest of California were purchased as part of the Treaty of Guadalupe Hidalgo , thereby becoming part of the United States . Los Angeles was incorporated as a municipality on April 4 , 1850 , five months before California achieved statehood . The discovery of oil in the 1890s brought rapid growth to the city . The completion of the Los Angeles Aqueduct in 1913 , delivering water from Eastern California , later assured the city 's continued rapid growth .   Nicknamed the `` City of Angels '' , Los Angeles is known for its Mediterranean climate , ethnic diversity , and sprawling metropolis . The city is also one of the most substantial economic engines within the nation , with a diverse economy in a broad range of professional and cultural fields . Los Angeles is also famous as the home of Hollywood , a major center of the world entertainment industry . A global city , it has been ranked 6th in the Global Cities Index and 9th in the Global Economic Power Index . The Los Angeles combined statistical area -LRB- CSA -RRB- also has a gross metropolitan product -LRB- GMP -RRB- of $ 831 billion , making it the third-largest in the world , after the Greater Tokyo and New York metropolitan areas .