have been restored to their original appearance. After the roof collapse, subsequent fundraising and restoration allowed the museum to upgrade many of its facilities. In 2005 the museum opened a new service facility west of the roundhouse for restoration of historical equipment and maintenance of active equipment. Collection The B&O Railroad Museum possesses the oldest and most comprehensive American railroad collections in the world. Dating from the beginning of American railroading, the collection contains locomotives and rolling stock, historic buildings, railroading artifacts, and an extensive archives and research library that document the impact of American railroading and the Baltimore & Ohio Railroad on American economics, culture, and history. The collection is being made available through an online searchable database. Notable rolling stock The museum's rolling stock collection include both originals and replicas, some of which were built by the B&O for its centennial "Fair of the Iron Horse" in 1927. Collection highlights include: Baltimore and Ohio 4-4-0 #25 William Mason built in 1856, used in The Great Locomotive Chase, and later in Wild Wild West. Operated until October 2014, retired from service due to thin crown sheet. Baltimore & Ohio 0-4-0 "Tom Thumb" 1927 replica. Had been refurbished by the Strasburg Rail Road and restored to operating condition for 2004 "Fair of the Iron Horse." Only operated a handful of times, at most, after refurbishment. On display in the roundhouse, in non-operational condition. In need of Federally mandated boiler inspection to operate again. Last operated circa Christmas 2013. Baltimore & Ohio 0-4-0 #8 "John Hancock" built in 1836. Baltimore & Ohio 4-2-0 #13 "Lafayette" 1927 replica. In the past, it was occasionally fired up and operated by the museum for demonstration purposes, currently on display in the roundhouse, in non-operational condition. In need of federally mandated boiler inspection to operate again. Last operated circa October 2015 Cumberland Valley 2-2-2T #13 "Pioneer" built in 1851. On loan. Baltimore & Ohio 4-6-0 #305: (Built in 1869 at Mt. Clare, Mother Hubbard design based on Ross Winans' design. Previously #217.) Baltimore & Ohio 4-6-0 #147 "Thatcher Perkins" built in 1863. Baltimore & Ohio 0-8-0 #57 "Memnon" built in 1848. Baltimore and Ohio 2-8-0 #545 A.J. Cromwell built in 1888. Baltimore and Ohio 2-6-0 #600 "J. C. Davis" built at Mt. Clare in 1875, which won first prize at the 1876 Centennial Exposition. St. Elizabeth's Hospital 0-4-0T #4: one of the last Porter steam