Fort Wool was one of more than forty forts started after the War of 1812, when British forces sailed the Chesapeake Bay to burn the Capital. This program was later known as the third system of U.S. fortifications. Designed by Brigadier General of Engineers Simon Bernard, an expatriate Frenchman who had served as a general of engineers under Napoleon, Fort Wool was constructed on a shoal of ballast stones dumped as sailing ships entered Hampton's harbor, and was originally intended to have three tiers of casemates and a barbette tier with 216 muzzle-loading cannon, although it never reached this size. Only two-thirds of the fort's bottom two tiers were completed. Fort Wool was built to maintain a crossfire with Fort Monroe, located directly across the channel, thereby protecting the entrance to the harbor.