The United States built Turtle, the submarine used in an unsuccessful 1776 attack on a British warship.
American inventor David Bushnell designed Turtle during the American Revolutionary War. The one-person craft was shaped like two joined tortoise shells and was intended to approach enemy ships underwater and attach an explosive charge to their hulls.
On 6 September 1776, Sergeant Ezra Lee piloted Turtle toward HMS Eagle in New York Harbor. He attempted to drill into the ship’s hull, but the vessel’s copper sheathing prevented the explosive from being attached. Turtle withdrew, and the attack failed.
Turtle did not sink a ship, but it is widely recognized as the first submarine used in combat. Its hand-powered propeller, ballast system, and underwater attack concept influenced later submarine development.