The Continental Army first occupied West Point, New York, on 27 January 1778, and it is the oldest continuously operating Army post in the United States. Between 1778 and 1780, the Polish engineer and military hero Tadeusz Kościuszko oversaw the construction of the garrison defenses. However, Kościuszko's plan of a system of small forts did not meet with the approval of New York Governor (and General) George Clinton or the other general officers. It was determined that a battery along the river to annoy the shipping was more appropriate, and Washington's chief engineer, Rufus Putnam, directed the construction of a major fortification on a hill 500 feet above sea level that commanded the West Point plain. General Alexander McDougall named it Fort Putnam. The Great Hudson River Chain and high ground above the narrow S curve in the river enabled the Continental Army to prevent British Royal Navy ships from sailing upriver and thus dividing the Colonies. While the fortifications at West Point were known as Fort Arnold during the war, as commander, Benedict Arnold committed his act of treason, attempting to sell the fort to the British. After Arnold betrayed the patriot cause, the Army changed the name of the fortifications at West Point, New York, to Fort Clinton. With the peace after the American Revolutionary War, various ordnance and military stores were left deposited at West Point.