Mars Bluff, an unincorporated community in Florence County, was once home to prominent plantations such as Red Doe and The Columns. In the latter half of the nineteenth century, after the close of the Civil War, it became a stronghold of tenant farming. Mars Bluff is famous as the site over which a United States Air Force pilot inadvertently released a nuclear bomb, creating a crater some 30 feet deep and 75 feet wide. Mercifully the bomb did not have a trigger and no one was killed (though several were injured). Mars Bluff was originally spelled Marrs Bluff.