Signal Hill, built around 1900, was originally known as Mount Castle. The large, two-story brick farmhouse was the home of John R. Duncan, a prominent Culpeper County dairyman and horse breeder. Situated on 40 acres of farmland, the house and outbuildings exemplify Culpeper County’s agricultural heritage of the late 19th and early 20th centuries, a period in which the small family farm gradually transformed into the modern paradigm of mechanization. The Culpeper County house is one of the county’s finest examples of turn-of-the- century domestic architecture. Its late Victorian character and design illustrates an era when railroads, modern sawmills, architectural and millwork catalogs, and a booming timber industry made a broad range of excellent domestic designs available to builders in rural and urban areas.