During the Dakota War of 1862 a citizen soldiers company was mustered in by Fort Commandant Captain J. Van Der Horck and commanded by Captain T. D. Smith. Another unit was Captain Ambrose Freeman's Company of Mounted Men, the "Northern Rangers." In August 1862 its defenses were tested. When increasing Indian activity by reconnaissance parties, drove nearby settlers into the fort's stockade. The Sioux besieged Fort Abercrombie for almost six weeks, alternating between occasional sniping and all-out attacks on all four sides of the fort. The garrison and settlers with rifles, shotguns, and howitzers held the fort.