Mount Clare is considered to be the birthplace of American railroading. It holds the oldest passenger and freight station in the United States and the first railroad manufacturing complex in the country.
The first Mount Clare Station building was erected in 1830 after Charles Carroll deeded the land to the Baltimore & Ohio Railroad Company. In May of that year, the first railroad was completed to Ellicott's Mills (now Ellicott City) at a distance of about 13 miles. The first passenger car to make the trip was the horse-drawn "Pioneer" which made the trip on May 25, 1830 in one hour and five minutes. On August 28 of that year, the first American locomotive, "Tom Thumb", made its debut run on the same route, but took ten minutes longer than the horse-drawn Pioneer.
The manufacturing complex at Mount Clare became a leading innovator in locomotive technology. Phineas Davis and Ross Winans created the first commercially practical coal-driven American locomotives at the site. In 1850, the B&O erected an ironworks where the first iron railroad bridge was designed. The circular roundhouse was completed in 1884 and was at the time the largest circular building in the world.
The Mount Clare Station is now part of the B&O Railroad Museum. The museum has the largest collection of 19th-century locomotives in the United States. Visitors can take take a train ride on the first mile of railroad tracks laid in the country.