Ft. Beauregard was an enclosed casemated earthen Confederate fort on a hill in Harrisonburg, Louisiana on the Ouachita River. It was built in 1862 to protect Monroe, Louisiana from Federal gunboats that might go up the river. The Confederates also used it as a supply line. The fort commander was Gearge W. Logan of the 2nd La. Heavy Battalion.
On May 10, 1863, four Union gunboats exchanged fire with the artillery and infantry from the fort which was protected by breastworks 8-10 feet high. The Federals fired about 150 shots with little damage to the fort and town. The gunboats were driven off by the garrison of the fort. There were wounded on both sides.
On September 3, 1863, Union Army Brig. Gen. M.M. Crocker reached Trinity, Louisiana with a heavy force and engaged the Confederate cavalry. Confederate Lt. Col. Logan, after having a council with his commissioned officers, determined to evaluate the fort, having only about 40 men fit for duty.
Logan evacuated the fort about 4:15 a.m. on September 4th. His men were able to save all of their wagons, horses, mules and most of their provisions. They were also able to save four of their best artillery pieces, three 3-inch guns and one 12 pounder howitzer. Next, they set forth on fire to prevent it from falling into the hands of the Yankees.
On the morning of the 4th, the Union 3rd Brigade rached Harrisonburg between 10 and 11 a.m. The fort and town had been evacuated. Fires were burning in the casemates and over the magazines. A large amount of ammunition had been destroyed.
The Yankees ravaged the fort destroying ammunition and provisions. Before leaving, they took two 6 pounder artillery pieces with them. They also destroyed a nearby grist mill and 57 bales of cotten marked “C.S.A”.