[3][4] Fort Knox also serves as the entry site for the observation tower of the Penobscot Narrows Bridge that opened to the public in 2007.

The Americans lost 43 ships and suffered approximately 500 casualties in the worst naval defeat for the United States prior to the Japanese attack on Pearl Harbor.

The American defeat contributed to the post-war movement for Maine's statehood, which occurred in 1820, as Massachusetts had failed to protect the region.

During the American Civil War volunteers from Maine, mostly recruits in training before assignment to active duty, manned the fort.

Thomas Lincoln Casey supervised work on the fort, including adapting the batteries to use the recently invented Rodman cannon, and oversaw its completion.

A plaque at the fort describes the laying of a controlled minefield in the river during this war, which Congress appropriated $3,200 for shortly after its outbreak.

[9] The garrison was reduced to one man, the "Keeper of the Fort" or caretaker with the rank of ordnance sergeant, at the end of the war.

[3] A work crew from the Ellsworth camp of the Civilian Conservation Corps, Co. 193 was deployed to transform the fort into a tourist destination.

The Friends reached an agreement with the State Department of Conservation to take over day-to-day operations of the Fort, and began doing so on April 15, 2012.

[11] Fort Knox was featured as one of the haunted locations on the paranormal TV series Most Terrifying Places in America in an episode titled "Cursed Towns" that aired on the Travel Channel in 2018.