Headquarters Farm mill was built in 1735 as part of the current farm estate. The 35'X 55' limestone or light colored sandstone mill is 3.5 stories in height. A mural on a wall in the dining room of the farmhouse shows the house and mill. The mill is shown with an exterior waterwheel, seemingly an undershot wheel. Not sure if this is historically correct or just a fancy of the artist.

Tradition has it that George Washington "commandeered" the house for his use prior to crossing over into Pennsylvania in the late fall/early winter of 1776. His troops were bivouacked in the town, hence the name of the town and farm became associated with the name, Headquarters. Washington later moved across into Penna. where he executed the daring Chistmas Eve crossing of the Delaware River in dense fog to surprise the Hessian soldiers there on Christmas morning 1776. This scene is immortalized in Imanuel Luytze's painting of the same and also on the reverse of the new state quarter commemorating New Jersey Statehood.

The house was started in 1735 with the basement and mill being the main structures. Two years later the first floor was added, then after the acquisition of the property by well-heeled John Opdycke in 1754, the second and half stories were added to the farmhouse in 1758. The mill was also added onto, being extended 15' toward Rosemont-Ringoes Road.

Some printed information adapted from an article, "Delaware Township, N.J." in the August 1987 issue of Colonial Homes Magazine.