More than a dozen forts were built to defend New York Harbor during the War of 1812. The Southwest Battery was constructed from 1808 to 1811 on a small island connected to Manhattan by a causeway. Although fully armed and staffed, it never fired upon an enemy. In 1817 it was renamed after New York mayor DeWitt Clinton. The army vacated in 1821 and the structure was deeded to the city.
In the summer of 1824, a new restaurant and theater opened at the site, now called Castle Garden. A roof was added in the 1840s, and Castle Garden served as an opera house and concert hall, featuring, among others, the Swedish soprano Jenny Lind, the most popular singer of her day, until 1854. From 1855 to 1890, it was an immigrant processing depot where more than 8 million people first set foot on U.S. soil. (Ellis Island assumed this function in 1892.) During the late 19th century the water between the island and Manhattan was displaced by a landfill, creating Battery Park. In 1896, McKim, Mead & White remodeled the fort, which then served as the New York Aquarium until 1941.
Restored to designs by Beyer, Blinder, Belle in 1986, today it's a monument and a museum where costumed interpreters describe harbor defenses during 1812.
No child who loves to play in forts, imaginary or real, will want to pass up a chance to visit Castle Clinton. A 30-minute tour and history, geared toward children, is offered several times daily.
Castle Clinton Tour: The 30-minute tour focuses on the history of the site and all of its incarnations. It includes a brief history of the War of 1812 and the fortifications built around New York Harbor to protect it from the British.
American History at the Battery: The 60- to 75-minute program includes a comprehensive history of New Amsterdam, as New York was once known, from the arrival of Europeans in the 17th century through the American Revolution, War of 1812, and 19th- and 20th-century urban growth up to the designation of Castle Clinton as a National Monument in 1950.