Take a walk through the history of American railroad, which started here in 1827 when the B&O Railroad was chartered and where the Tom Thumb, the first locomotive, was built. Powerful locomotives, humble boxcars, and delicate 1830 coaches are among the stock inside the Mt. Clare Roundhouse, fully accessible for visitors with disabilities or strollers. All but one of the pieces damaged when the roof collapsed in 2003 have returned to the floor, fully restored and beautifully painted. But don't stop here. Head outside to the platforms or to the north car shop to see even more locomotives from railroading's heyday. Stop in the theater car for a video on model railroads. Speaking of model railroading, look for the Smithsonian Treasures cases in the gallery, the model train layout, and train garden behind the roundhouse—and in December, the remarkable train layouts that spread out inside the roundhouse. Three great walking tour brochures help visitors learn more about steam power, model railroading, and train history. A commemoration of the Civil War sesquicentennial, "The War Came by Train," continues through May 2015. Mascot "Choo Choo Blue" points out exhibits kids might like, including a pint-size train through Choo Choo Blueville. Of course, those who want to ride a real train can climb aboard for a one-mile trip down some of the oldest track in the country. They cost $3 and are offered weekends in January and from April to December Wednesday through Friday at 11:30am, Saturdays at 11am, 1pm, and 2:30pm, and Sunday at 12:30 and 2:30pm.