5. Madison Square Park used to be a cemetery, arsenal, military parade ground, and house of refuge
Madison Square Park, perhaps unsurprisingly, used to be a cemetery (Herald Square, Union Square, and others in New York City were once cemeteries as well). It was also a potter’s field (a burial ground for those who died unknown or couldn’t pay for a burial in other cemeteries), between 1794-1797, but the field moved to Washington Square Park.
After its time as a potter’s field, the land became the site of a U.S. Army Arsenal and then a military parade ground that was named “Madison Square” in 1814. Both made for a key military post for drills during the War of 1812. Once the arsenal lost its military usefulness in 1825, it became a “House of Refuge” for juvenile delinquents until 1839 when a fire destroyed it. The land between 23rd and 26th Streets from Fifth Avenue to Madison Avenue officially became a public park with a fence in 1847.