The Columbian was a named passenger train operated by the Baltimore and Ohio Railroad. It was the all-coach supplemental train of the all-Pullman Capitol Limited. It operated from 1931 to 1964. The train's initial route was between Jersey City, New Jersey and Washington, D.C., but in 1941 the Columbian route was lengthened to Jersey City – Chicago, Illinois. It was the first air-conditioned train in the United States.