Fears that the Confederate navy might travel up the Kennebec River and attack Augusta, Maine, led to the construction of Fort Popham in 1862. Built near a site colonized in pre-revolutionary days by George Popham, the walls form a crescent shape. Their granite blocks glow golden in the late afternoon sun. The artillery consisted of thirty six cannons that were arranged on two levels; each cannon weighed 25 tons and fired solid shot, each weighing almost 480 pounds. The fort was reactivated during the Spanish-American war and World War I.