Construction began on Fort Hancock in 1857 to help increase U.S. coast security. It was initially designed by U.S. Army Corps of Engineers Captain Robert E. Lee. Lasting only a few years before it was deemed to be too vulnerable to rifled guns, the fort was loaded up with many different types of weapons and converted to the Sandy Hook Proving Ground, a weapons testing site.
Due to its firepower, it became one of the primary defensive locations for New York City during World War I, and later a staging area for troops heading to battle in World War II. After World War II, it became home to strategic defensive weapons, including Nike Missiles, during The Cold War.
Decommissioned in 1974, Fort Hancock is now part of the Gateway National Recreation Area.