Last of a series of forts which, from the Dutch ssettlement of 1624, guarded lower Manhattan, this structure was built by the United States in the years 1808 to 1811. It was first called "West Battery," and was one of the important defenses of New York Harbor during the War of 1812 period. Named in honor of Gov. DeWitt Clinton in 1815, in that year it was made headquarters, U.S. Third Military District. From 1816 to 1820 Gen. Winfield Scott was in command. The Headquarters was removed from Castle Clinton to Governors Island in 1820.
Ceded to New York City in 1823, Castle Clinton was renamed Castled Garden in 1824. Until 1855 it served as a public center and theater where public figures, including lafayette, Kossuth, and President Jackson, were received, and artists such as Jenny Lind were presented. From 1855 to 1890, the structure was the nation's principal immigrant depot, with over 7 million immigrants entering its portals - the "Gateway to the New World." Between 1896 and 1941 the old structure served as the New York City Acquarium. It was created a national monument in 1950.