 In the American colonies and the United States, coastal forts were generally more heavily constructed than inland forts, and mounted heavier weapons comparable to those on potential attacking ships.Coastal forts built from 1794 through 1867 were generally grouped into three time periods by later historians; these were marked by significant federal fortification programs with most forts built in a particular style.Forts of the first and second systems were generally earthwork star forts with some masonry reinforcement, mounting one tier of cannon, usually on the roof of the fort or behind low earthworks.