The number 25 served on the Baltimore and Ohio for nearly forty years. The locomotive is one of the engines that pulled the train which carried Abraham Lincoln from Springfield, Illinois, to Washington, D.C., for his inauguration in 1861. It was renumbered to 55 in 1882 and was retired in 1892 when it was placed in storage. Fortunately, the Baltimore and Ohio had greatly favored its locomotives, and preserved its best examples, including number 25. The engine was displayed at the Chicago's World Fair of 1893, then at the St. Louis Exposition of 1904. In 1927, the number 25 was given the name "William Mason" in honor of its builder, and was exhibited at the railroad's own Fair of the Iron Horse, then at the 1939 New York World's Fair, and finally in 1948 at the Chicago Railroad Fair. During 1951, the engine was loaned to the Erie Railroad, operating as a traveling exhibit as part of the railroad's centennial celebration. When not being exhibited, it remained in storage until 1953, when it was placed on display in the newly opened Baltimore and Ohio Railroad Museum, where it currently remains.