The city of Los Angeles remained within its original 30 square-mile area until the 1890s. The earliest significant additions to the city were the counties of Highland Park and Garvanza to the north, and the South Los Angeles region. In 1906, the approval of the Port of Los Angeles and an adjustment in state law enabled the city to absorb the Harbor Gateway, a narrow strip of land going from Los Angeles towards the port. San Pedro and Wilmington were added in 1909, and the city of Hollywood was added in 1910, making the city 90 square miles.
Also annexed that year was Colegrove and Cahuenga, as well as part of Los Feliz. The establishment of the Los Angeles Aqueduct provided the city with four times as much water as it required, and the availability of water service became an effective lure for neighboring cities. Los Angeles administrators locked in customers through annexation by declining to supply other areas. By residential vote, 170 square miles of the San Fernando Valley were annexed to the city in 1915, nearly tripling its area. Over the next two decades dozens of new additions brought the city's area to 450 square miles.
Presently, it is approximately 470 square miles. In World War II, Los Angeles grew as a locus for production of war materials and munitions. Many African Americans and white Southerners relocated to the area to fill factory positions.
By 1950, L.A. was an industrial and financial giant due to war production and migration. The city made more automobiles than any city other than Detroit, made more tires than any city but Akron, and stitched more clothes than any city except New York. Additionally, it was the national center for the creation of motion pictures, radio broadcasts and television shows.
Building and construction greatly expanded as tract houses were built in suburban areas financed by the Federal Housing Administration. The city continued to spread out, particularly with the annexation of the San Fernando Valley and the building of the freeway system in the 1940s. When the local streetcar system went bankrupt, L.A. became a city built around the motorcar.
Matt Paolini is a architectural specialist for CityBook, the family-safe yellow pages online, which carries an extensive directory on Los Angeles swimming pool coping, plastering and tiling.