Fort Foster State Historic Site is part of Hillsborough River State Park, located on the east side of U.S. 301 from the park.
During the Second Seminole War, the purpose of Fort Foster was to defend the bridge crossing at the Hillsborough River and act as a resupply point for the soldiers in the field. The fort was garrisoned on and off from December 1836 through April 1838.
Although the fort was attacked on several occasions, the worst attack occurred in February 1836, when a small group of Seminoles attempted to set fire to the bridge. The attempt was thwarted by aggressive musket and cannon fire from the 50 or so U.S. Navy sailors and the 20 artillery men within the fort.