Fort Monroe occupies land that was originally Fort Algernourne in the early 17th century although it only lasted a few years before being burned to the ground.
Fort George occupied the site in the 18th century but it was destroyed by a hurricane in 1749. In 1819, the largest stone fort built by the Army was constructed on the same spot because of its strategic location. Finally completed in 1834, it was known for a while as the Gibraltar of Chesapeake Bay. The Army base played a big part in the Civil War as well.
After Virginia decided secession from the Union was in order, President Lincoln fortified Fort Monroe so it wouldn’t fall to the Confederate Army, which it didn’t for the entire duration of the war.
Modernization occurred in the 20th century, maintaining it as one of the most heavily defended places in the United States. It played a major role in protecting the area during both of the World Wars. The cannons gave way to impressive artillery over the years. Some of the modern guns could fire 25 miles away.
After World War 2, however, even that range became obsolete because of bombers and missile technology. Gradually the guns were removed and the role of Fort Monroe changed to that of training. It now houses the United States Army Training and Doctrine Command.