Fort Popham was built in 1862, as fortification to protect Maine's capital city of Augusta from invasion by the Confederates during the Civil War. The granite blocks, which formed the walls of the fort, were obtained from Fox Island and Dix Island. The walls of the fort facing the Kennebec River were 30 feet high and formed a crescent shape.

The artillery at Fort Popham consisted of thirty-six cannons that were arranged in two tiers of casements. Each cannon weighed roughly 25 tons and fired solid shot, each weighing almost 480 pounds.

Fort Popham was reactivated during the Spanish-American War and during World War I. The construction of Fort Baldwin rendered Fort Popham obsolete. Fort Baldwin's guns had a longer range. The fort is only two miles from Popham Beach State Park and has become a popular tourist attraction.

Fort Popham is open to the public from Memorial Day through September 30. In addition to viewing this historic site, you can also enjoy picnicking and fishing.