Casper Lipe settled the fort’s property around 1730 constructing a stone house overlooking a stream in the Palatine German tradition. On the high-plateau hilltop above these homes is the site of Revolutionary War Fort Plain, the northwest exterior blockhouse and the entire fortified hilltop complex. Evidence suggests a fort was originally constructed on the southeast corner of the hilltop during the first French & Indian War around 1740. It protected the local settlers as well as the Mohawk Indian Castle of “Canajohari” located on the adjacent Sand Hill.
Earliy in the war the Continental Army was assigned to nearby Fort Plank, a fort located about 3 miles southwest of Fort Plain. That fort, with its view of the Cherry Valley hills, was ideally suited to guard the southerly approaches to the valley. By the summer of 1780 General Robert Van Rennselaer had made Fort Plain his new headquarters in the valley. Van Rennselaer had been given command of the battered Tryon County Militia after the death of General Herkimer at the Battle of Oriskany. The new general however was not well received in his new position. When the valley came under attack at Stone Arabia and again at Klock’s Field, Van Rennselaer failed to act properly. The severe criticism and court martial which followed discouraged use of the name “Fort Rennselaer” and the military headquarters became known, for a time, as Fort Plain instead.
The following winter Governor Clinton, with the blessing of General Washington, asked Marinus Willett to take command of the upstate New York forces. Willett, utilizing Fort Plain as his headquarters, was given the task of coordinating the defense of the Mohawk Valley. Through a system of couriers he maintained communications with all points in the valley. This system allowed for the quick response of forces where needed. The Patriot victories at New Dorlach (Sharon Springs) and Johnstown are both attributable to this strategy.
Fort Plain is also responsible for launching a failed attack on British held Fort Ontario in Oswego. Under secret orders from General Washington, Marinus Willett departed Fort Plain in January 1783 to seize Fort Ontario in a surprise nighttime raid. Losing its way in the freezing night the army failed to surprise the fort and was forced to return to Fort Plain without accomplishing its mission. In July of that same year with a peace treaty looming on the horizon
General Washington decided to visit Fort Plain. He arrived to the cheers of the fort’s garrison on July 28th, 1783. The fort continued in use as a military storehouse until about 1810 when the last of the fort’s buildings, the northwest blockhouse, was taken down. The property once again became part of the Lipe farm. Timber and stone remnants of the fort were incorporated into other buildings as the modern village of 19th century Fort Plain took shape.