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 Illinois. It was the first air-conditioned train in the United States. History The Columbian between Jersey City and Washington was the first air-conditioned passenger train in North America. Air-conditioned equipment began operating on the train on May 24, 1931. In 1937 the B&O re-equipped the Columbian with cars from the Royal Blue. On December 19, 1941 the B&O extended the Columbian from Washington to Chicago. To support the longer service the Columbian again received cast-offs from the Royal Blue, plus other equipment. The Columbian operated in tandem with the all-Pullman Capitol Limited, running thirty minutes behind. The Capitol Limited conveyed the Columbians coaches between Jersey City and Washington. During World War II the Columbian'''s consist swelled to 14 cars. In 1949, a brand new lightweight Columbian train set for travel between Baltimore, Maryland, via Washington to Chicago was built. The consists were ordered from Pullman-Standard for April, 1949 delivery and these two train sets have the distinction of being the only all-new consists built for the B&O in the postwar period. These two eight–car streamlined trains were the first trains in the eastern U.S. to be equipped with dome cars, the "Strata-Dome". Although the pair were intended as a daytime operation between Chicago and Baltimore by way of Washington the two new trains entered overnight service May 5, 1949. In the 1950s saw a wave of consolidations as the B&O's passenger services contracted. The Columbian and Ambassador (which served Detroit, Michigan) began joint operation between Washington and Willard, Ohio on January 10, 1954. On December 1, 1957, the Columbian's dining car stopped operating west of Willard. On April 26, 1958, the B&O discontinued all passenger service between Jersey City and Baltimore, Maryland, and thereafter the eastern terminus of the Columbian was Baltimore. At the same time the Columbian and Capitol Limited began joint operation between Washington and Baltimore. On October 26, 1958, this joint operation extended all the way to Willard, ending the independence of both trains. The B&O dropped the Columbian name altogether on April 26, 1964. When Amtrak took over train service on May