John D. Spreckels' San Diego Electric Railway (SDERy) made regular stops at the station since its opening, and continued to do so until April 24, 1949, when San Diego adopted an all-bus transit system. Spreckels' other rail-related concern, the San Diego and Arizona Railway (built in part to provide San Diego with a direct transcontinental rail link to the east by connecting with the Southern Pacific Railroad lines in El Centro) was invited to make use of the facility. The first SD&A passenger train arrived in downtown on December 1, 1919. In 1936 the Santa Fe ordered a six-car trainset from the Budd Company specifically for the initiation of a new, streamlined named train between the LAUPT and San Diego. On March 27, 1938, the company inaugurated the "San Diegan" route, operating on a two-hour-and-30-minute schedule. A second "San Diegan" consist entered service on June 8, 1941, doubling the schedule to four daily round trips. Freight service consisted of one scheduled overnight train per day, though extras were run as required (sometimes numbering as many as 10–12 per day). The United States' entry into World War II saw a significant increase in rail traffic to and from San Diego, both in the form of troop movements and transport of military vehicles and supplies.