Adamstown lies in the fertile valley between Sugarloaf and Catoctin Mountain on the former Carrollton Manor, a estate originally owned by Charles Carroll of Carrollton. Until 2000, it was a little-altered representative of mid-19th century linear town planning. It is significant in architecture for its variety of structures, including residential, commercial, industrial, educational, agricultural, and religious buildings. The late 18th century road from Jefferson to Greenfield Mills on the Monocacy River, originally called the Bridal Road, followed the route of the present-day Mountville Road. The 1832 arrival of the railroad to the manor created the economic and transportation impetus for the development of the community.