The branch opened in December 1831 with a ceremonial train, pulled by horses, carrying directors of the B&O and various politicians from Baltimore. In planning the route of the Old Main Line, the B&O decided against building the main line directly through Frederick, preferring instead to take advantage of a valley grade to the south of the city. The city's first train station, built in 1832 at South Carroll Street, was the B&O's second oldest permanent station, and was used mainly for freight. A new passenger depot was built in 1854 at East All Saints and Market Streets, and the old station continued as a freight station until circa 1910. A station at Frederick Junction was opened after the Civil War and operated through the World War II era.