As California's population grew, however, the district generally was moved northward, eventually to the San Francisco peninsula.

[4] Richard Nixon, who would subsequently serve as the 37th president of the United States, represented this district from 1947 to 1951, when it was located to the east of Los Angeles.

Nancy Pelosi, the former speaker of the House, represented the district from 2013 to 2023, when it covered most of San Francisco.

Alongside Oakland, the 12th district takes in the cities of Alameda, Albany, Berkeley, Emeryville, Piedmont, and San Leandro.

Technically, the western most tip of Alameda Island is part of the City and County of San Francisco.