American Flyer Stock Cars were designed to replicate live stock transport rail cars. The cars were made between 1946 and 1953. Gilbert only produced 7 different Operating Stock Cars. The main variations were couplers, colors and styles.
There were three railroad lines that were used with the Gilbert Operating stock cars. These included the Missouri Pacific, Union Pacific and Northern Pacific. The first to be modeled by American Flyer was the Missouri Pacific Railroad. The Missouri Pacific Railroad was the first railroad west of the Mississippi. The railroad was later merged with Union Pacific Railroad hence the change by Gilbert. The Northern Pacific ran from Minnesota to the west coast.