Description: Horn's Hook Battery, also known as Fort Horn's Hook and Thompson's Battery, was a nine-gun battery planned in February 1776 to defend Manhattan Island during the Revolution. It was located at what is now the intersection of 89th Street and East End Avenue, opposite Ward's Island and Hell Gate. In September 1776, the fort came under fire from British forces stationed in Queens. During the British occupation, the battery was restored and additional palisades and supporting batteries, as well as a blockhouse were added. After the war, the new owner, Archibald Gracie, leveled the works in 1794 and erected a mansion, which now serves as the home of the city’s mayors.