The Spanish had established Los Angeles, one of the oldest cities in the Far West, in 1781 to help colonize the region. For several decades, the city was the largest center of population in Mexican California. Mexican settlement and development of California, however, proceeded very slowly, and Los Angeles developed little real economic or political power during this period. By the time the U.S. took control of California in 1848, Los Angeles still only had just over 1,610 inhabitants.
As Anglo-Americans began to assert their control over California, they gradually broke up the large Hispanic ranches and replaced them with a more diversified farming economy. With irrigation, southern California proved an ideal environment for growing many crops, particularly valuable fruits like oranges. During the 1870s and 1880s, state railroad lines linking Los Angeles into the new system of transcontinental railways created additional moneymaking opportunities. Settlers, tourists, and health seekers all boarded trains to travel to the Pacific, where the sunny climate and beautiful scenery promised a new and better life.
The healthful new California lifestyle became closely associated in the public mind with the sweet fruits that grew so abundantly in the orchards around Los Angeles. Taking advantage of the rapid transportation capabilities of the transcontinental lines, Los Angeles area orchard owners began shipping their oranges to the East in 1886. As the city grew, it subdivided many nearby orchards and pushed the orange growers out into regions like Orange County. There the orange growers steadily increased the size of their orchards to the point where local supplies of water for irrigation were inadequate. Determined to sustain their agricultural and real estate booms, Los Angeles residents undertook a massive program of hydraulic engineering in the late 19th and early 20th centuries. Engineers took water from the distant mountains to transform the arid southern California ecosystem into a green agricultural and residential paradise.
The resulting growth was astonishing. In 1880, just before the first trainload of oranges departed, Los Angeles had 11,183 inhabitants. A decade later, the population had ballooned to 102,479. By 1920, there would be more than half a million residents. Los Angeles was already well on its way to becoming the largest urban center in the American West.