Los Angeles is the largest city in California. It was annexed with the U.S. after the Mexican American War in 1846. The railroads arrived into Los Angeles in 1876, and the city was linked with the rest of United States. Petroleum was discovered in the city and the surrounding area in 1892, and by 1923, the city had become the largest oil producer. At the dawn of the 20th century, the population had grown to over 102,000.
In 1910 Los Angeles annexed the town of San Pedro. In 1910, Hollywood entered into the city and D.W. Griffith was among the first directors to film in L.A., And within the next ten years, the city would have become the centre of the entertainment industry. The population multiplied in two decades from 102,000 in 1900 to over one million in 1924. The city hosted the Summer Olympics of 1932. During World War II, Los Angeles was a major centre of wartime manufacturing, such as shipbuilding and aircraft. Over 1000,000 workers were employed in aircraft manufacturing and shipbuilding.