In the late 18th century, the Spanish Governor of California decided to establish a pueblo along the River Los Angeles north of the Mission San Gabriel. He needed to reaffirm Spain's claim over the territory in the face of encroachments by Russia in the north and Britain from the sea. Spain approved his request and plans were drawn up.

Settlers for this pueblo, however, were hard to come by: The area was remote and desolate, and the journey there long and difficult. There were even rumors that the soldiers were not getting paid. Finally, however, the governor and a small band of settlers, along with soldiers, priests and a few Indians, arrived. On September 4, 1781, El Pueblo de la Reina de Los Angeles was founded. Of the original 11 heads of families, only four remained for the remainder of their lives. The others, disheartened by the difficulties they faced, moved to other locations within the state or returned to their original homes.

Each year Los Pobladores 200, an association of people who trace their lineage to Los Angeles' original settlers, make their "Historic Walk to Los Angeles" as part of the city's birthday celebrations. The three-hour trek begins at Mission San Gabriel and ends at Olvera Street in downtown LA, commemorating the first nine-mile leg of the 1781 original settlers.

The settlement of Los Angeles led to the decimation of the original tribes inhabiting the area through disease, and the eradication of tribal beliefs and customs through conversion to Christianity. The number of members of these tribes today is quite low and the groups are widely scattered.

During the time that Alta California belonged to Mexico, American immigrants faced deportation if they would not adopt Mexican citizenship and become Roman Catholic. The influx of US citizens continued, however, and in 1848 Mexico ceded Alta California to the United States. The population continued to swell, and on September 9, 1850, California became the 31st state of the Union. Today it is the third largest state (area-wise) and has the largest population. Los Angeles is not only the largest city in California, but also is the second most populous municipality in the nation (New York City is first).