On November 14, Thomas Pell of Fairfield, Connecticut buys a large track of land from the Siwanoy Indians, including what will become known as Hart Island. 1774 Pell heirs sell to Oliver DeLancey what will become known as Hart Island. 1775 Map refers to it as Heart Island, perhaps because of its seeming shape when seen from a boat circling it.
Maps start referring it as Hart Island.
Other names have been Little Minneford Island and Spectacle Island. The 25th Calvary musters in during February, March, and April, the earliest known recorded mustering on the island of Union recruit units in Civil War. Facilities on the island housed between 2,000 and 3,000 recruits and over 50,000 men were trained there. The 31st United States Colored Troops Regiment is organized on Hart during April 1864, one of New York State's three USCT regiments. Some 4,000 African American volunteers form New York's 20th, 26th and 31st USCTs.