Ownership of the Upper Mills, (and land known today as Philipsburg Manor) once belonged to British sympathizer Frederick Philipse the third, who fled America after the Revolution. The families vast holdings were confiscated and eventually sold off piece by piece. The Mills were purchased by Gerard G. Beekman Jr. a prominent New York businessman. The new Beekman estate expanded 900 acres and included present day Tarrytown and North Tarrytown (Sleepy Hollow).
After his death in 1822, his wife Cornelia sectioned off the land and sold it off as she was pressed for funds after her husband’s passing. Thus, Beekmantown was born and remained so until the Hudson River Railroad improved transportation between the tiny hamlet and New York City. The land eventually grew to a population of 2,500 and changed into the Village of North Tarrytown and later, Sleepy Hollow.