 By the 1890s the construction of electric railroads had begun in California and by the early 20th century several systems existed to serve California's largest cities.The state's electric railroad systems included the San Diego Electric Railway, Los Angeles' Pacific Electric system, the Los Angeles Pacific Railroad, East Bay Electric Lines and the San Francisco, Oakland, and San Jose Railway and Interurban rail systems such as the Sacramento Northern Railway were also constructed.By the 1920s, Los Angeles' Pacific Electric system was the largest electric railroad in the world.