Union City is crossed by three railroad lines, two running through Decoto and one running through Alvarado. In fact, Decoto was pretty much founded as a railroad town.

First Rail Line

The first railroad line built was the one in Decoto, furthest to the East (closer to the hills). It was build in 1867 by the Western Pacific Railroad. This line ran through Niles Canyon, and turned north to Oakland and south to San Jose. With the Central Pacific Railroad building the Transcontinental Line from Sacramento east, to make the final connection to the west coast, it needed a line running from Sacramento to Oakland. In 1869, the Central Pacific Railroad bought a number of railroads, including the Western Pacific, to make the link.

Decoto Station

The only station on the Central Pacific line in Union City was at Decoto. There was a small station, just outside of Union City (about where Alvarado-Niles road crosses the railroad tracks, called Pabrico.

The Decoto station was built in .. It was located on the east side of the tracks close to the corner of Decoto Rd. and Depot Rd.

The Decoto station was torn down in 1955.

Second Rail Line

The second rail line built in Union City was the Southern Pacific Coast Railroad. It was a narrow-gauge line built in 1878, running from Santa Cruz, through Alviso, over the bay marshes, through Newark, Alvarado, Mt. Eden (now part of Hayward), and eventually to Oakland. The line was bought in 1887 by the Southern Pacific Railroad. In 1906 the line was converted from narrow-gauge to standard gauge.

Alvarado Station

A depot station was built in Alvarado, close to where Smith St crosses the railroad.

A spur line was run to the Alvarado Sugar Beet Factory (later known as the Holly Sugar Factory) to haul beets to be refined and taking the sugar to market. The spur still exists and continues under I-880 to the concrete factory. It used to continue further up South Industrial Parkway, but was stopped to make way for a shopping center.

When the Holly Sugar Factory closed in 1969, there was no longer a need to for the Alvarado Depot, so in less than a year it was turn down.

Hall

Near where Alvarado Blvd. crosses the railroad line was the small station of Hall. Built for the John Hall ranch, it was nothing more than a shelter to keep people out of the rain while they waited for the train to arrive.

Third Rail Line

The third rail line built in Union City was built in 1909 by a the Western Pacific Railroad. This was not the same Western Pacific that was bought by the Central Pacific, but a wholly new railroad that just happened to reuse the Western Pacific name.

This line is the one that runs parallel with BART as it runs though Union city. The Western Pacific line ran through a newly laid run through Niles Canyon (which is still in use today). The Western Pacific Railroad was bought by the Union Pacific Railroad.

Decoto Station on the WP

The Western Pacific built a station in Decoto in 1910. It was eventually moved to San Jose in 1922.