Railroad - 8 of which traveled through the museum's historic site of Mount Clare. In 2021, the museum's Mt Clare Station building was designated as a National Park Service Underground Railroad Network to Freedom site. The museum also hosts an annual Day out with Thomas event every year, complete with the train's excursion including a non-powered Thomas the Tank Engine replica. History The inaugural horse-drawn B&O train traveled the of the newly completed track from Mount Clare to Ellicott Mills (now Ellicott City, Maryland), on May 22, 1830, the first regular railroad passenger service in the U.S. The existing Mount Clare station brick structure was constructed in 1851. The adjacent roundhouse designed by Ephraim Francis Baldwin was built in 1884 to service the B&O's passenger cars. For much of its history, the B&O had been collecting locomotives and other artifacts from its history for public relations purposes. This collection was stored in various places until the railroad decided to centralize it in a permanent home. The car shop of the Mt. Clare Shops was chosen, and the new museum opened on July 4, 1953. The museum ended up outliving its parent B&O Railroad, and was kept intact by both the Chessie System and CSX Corporation. In 1990, CSX deeded the property and collection to the newly formed, not-for-profit museum organization governed by an independent board of directors and provided it with a $5 million endowment. In 1999, the museum became affiliated with the Smithsonian Institution. In the early morning of February 17, 2003, heavy snow from the Presidents' Day Storm collapsed half of the roof of the museum's roundhouse. Although the structure's central support columns remained standing, the supporting iron struts and ties of the destroyed roofing sections failed under the snow load. The museum suffered heavy damage not only to the roundhouse itself but also to the collection within the roundhouse. Some of the items were damaged beyond repair. Reporting on the devastation the following day, The Baltimore Sun said, "...hours after the collapse, columns of mangled steel stuck out from the roundhouse ... Locomotives and passenger cars in the museum's collection, some dating from the 1830s, could be seen covered with snow and debris." The roundhouse, with a newly repaired roof, reopened to the public on November 13, 2004, and the damaged locomotives and cars were surrounded by a plexiglass barrier. As of September 2015, all damaged exhibits