Fort Constitution, which would have enclosed this area, was intended to be the major fortification for the defense of the Hudson River. In January 1776, after three months of construction, work on the fort was halted, for the fort was considered to be poorly designed, badly located, and unduly expensive. Only the blockhouse, the greatly modified western battery, and the neighboring barracks and storehouse were ever completed. Unlike nearby Marine Battery, none of these structures was rebuilt after being destroyed during the British operations on the Hudson in October 1777.
Sited on the knoll ahead was the octangular or circular log blockhouse, thirty feet in diameter, and "mounted with eight cannon, (four pounders,) pointed out the garret windows, and looks very picturesque" Behind and to the north was a one and a half story barracks, 100 feet long and 20 feet wide.