When the colonial administrators of New Spain founded Los Angeles in 1781, they granted the pueblo four square leagues of land—a grant that defined the city's limits when it incorporated under American law in 1850. For decades, Los Angeles confined itself much to its original borders.
Then, in the 1890s, it suddenly engorged itself on vast tracts of land. As the population boomed and development spilled outside the original city limits, Los Angeles annexed adjacent territory. The Western Addition brought present-day Koreatown into the city. The San Fernando Valley Addition—annexed just two years after the completion of the Owens Valley aqueduct—enlarged the city by 170 square miles. The oddest was the so-called Shoestring Addition, a long, narrow strip that connected the city with its harbor in San Pedro.
L.A. annexed other cities, too—or consolidated with them, to use the official terminology. Hollywood (annexed in 1910) was once its own independent city. So was Eagle Rock (1923), Venice (1925), and Watts (1926). For a time, it seemed that this process of consolidation would extend to every square mile of Los Angeles County; in 1916, a commission recommended uniting the city and county under one municipal government, using San Francisco as a model. But proudly independent cities like Long Beach rebelled against the idea, and today Los Angeles County is a patchwork of 88 separate municipalities.
The original pueblo land grant is outlined in yellow:
And here's the San Fernando Valley Addition, by far L.A.'s largest annexation: