This branch was originally constructed by a predecessor of the Santa Fe in the 1880s. At the time, it was believed that the Los Angeles Port would be constructed in the Santa Monica area. While a port and pier were constructed there, the "true" port was built further south, at San Pedro, in the 1890s. The lack of steady freight traffic caused the Santa Fe to lose interest in the route, and the consequently abandoned it in 1900.
Before it was dismantled, however, it was sold to the Los Angeles Pacific, which merged into the Pacific Electric in 1911. While the line never had much passenger service (discontinued in the 1920s), it continued to serve produce warehouses and other small businesses until the 1960s. Under the ownership of the Southern Pacific, most of the rails remained in place until 1977. By then, the line had modern girder bridges over the Ballona Creek and nearby storm channels, along with a couple of wig-wags and faded "Pacific Electric" wooden crossbucks.
As of 2003, only the Marina Del Rey crossing and one or two other isolated segments remain. The girder bridges and wig-wag crossbucks are gone. The line served Inglewood, Mesmer, Alsace, Alla (diamond with another PE line between Redondo Beach and Culver Junction), Machado, Ocean Park, and Santa Monica.