This mill is an important example of early 19th century technological innovation. Powered solely by a waterwheel, a combination of machinery automatically moves grain from one part of the mill to another through a sequence of continuous grinding and sifting steps to produce flour and meal. This integrated machinery greatly reduced the manual labor previously required to operate a gristmill. The mill stopped operating in the mid 1930s and stood abandoned for decades until it was acquired by Fairfax County, VA in the late 1960s. After extensive restoration, it was opened as a museum in 1972.

Link: http://www.fairfaxcounty.gov/parks/history.htm