Kansas City Union Station is a union station opened in 1914, serving Kansas City, Missouri, and the surrounding metropolitan area. It replaced a small Union Depot from 1878. Union Station served a peak annual traffic of more than 670,000 passengers in 1945 at the end of World War II, quickly declined in the 1950s, and was closed in 1985.

Kansas City, Missouri is the largest city in the U.S. state of Missouri by population and area. Most of the city lies within Jackson County, with portions spilling into Clay, Platte, and Cass counties. It is the central city of the Kansas City metropolitan area, which straddles the Missouri–Kansas state line and has a population of 2,392,035. As of the 2020 census, the city had a population of 508,090, making it the 37th most-populous city in the United States, as well as the sixth-most populous city in the Midwest. Kansas City was founded in the 1830s as a port on the Missouri River at its confluence with the Kansas River from the west. On June 1, 1850, the town of Kansas was incorporated; shortly after came the establishment of the Kansas Territory. Confusion between the two ensued, and the name Kansas City was assigned to distinguish them soon after.