Area codes 213, 323, and 738

In 1947, when the American Telephone and Telegraph Company (AT&T) devised the first nationwide telephone numbering plan and assigned the original North American area codes, the state of California was divided into three numbering plan areas: 213, 415, and 916, for the southern, central, and northern parts of the state, respectively.

In 1950, the boundary between 213 and 415 was realigned toward the north, requiring the southern portion of the Central Valley, including Bakersfield, to change from area code 415 to 213.

As a result of southern California's rapid expansion of telephone service during the second half of the 20th century, area code 213 was split five times in the period from 1951 to 1998.

The first split became necessary in 1951, when most of the southern and eastern portion, including San Diego and most of Orange County, were assigned area code 714.

This split made 213 one of the geographically smallest numbering plan areas in the nation, covering only Downtown Los Angeles and its immediately adjoining neighborhoods, such as Chinatown.