Beginning in 1826, the Baltimore and Ohio Railroad Company constructed a railroad line from Baltimore, Maryland to Cumberland, Maryland. This line passed through Martinsburg which is situated 100 miles in between these two cities. In this town, the Baltimore and Ohio company decided to build a roundhouse to maintenance passenger and freight trains on their way west.
The current Martinsburg Baltimore and Ohio Railroad Co. shop complex was constructed in 1866. It is comprised of the West Roundhouse, the Frog and Switch Shop, and the Bridge and Machine Shop. The other structures on the site (the East Roundhouse, the Saw House, and the Equipment Shop) were added to the Martinsburg complex in the late 19th and early 20th centuries. The shop complex is West Virginia's 16th National Historic Landmark.