In October of 1861, Confederate General M. Jeff Thompson led a force of 3,000 men into Southeast Missouri. On October 15, 1861, Thompson led a cavalry attack on the Iron Mountain Railroad bridge over the Big River near Blackwell in Jefferson County. The bridge was burned and Thompson retreated to join his infantry in Fredericktown. Here he found that strong Union forces were closing in on him.

Col. J. B. Plummer was sent from Cape Girardeau to Fredericktown with about 1,500 Union soldiers, while Col. W. P Carlin advanced from Pilot Knob with about 3,000 men. Learning that Union forces were approaching from east and west, Thompson began a withdrawal from Fredericktown south along the Greenville Road. By midnight, October 20, Thompson's forces had marched twelve miles south of Fredericktown.

At this point, Thompson decided to return with his infantry to attack Union forces along the road from Fredericktown to Jackson. Arriving before dawn on October 21st, Thompson positioned his force along the road, but finding that the Union soldiers had taken another route slightly north of the main road, he repositioned his battery in ambush just south of Fredericktown along the Greenville Road. It was here, on the afternoon of October 21st, the Confederate command was engaged by about half of the Union force sent in pursuit of Thompson.

The Union artillery was hauled out and the Seventeenth Iowa Regiment charged upon the Confederate battery, capturing one gun. The running battle lasted over four hours with the Confederates in halting retreat. Late in the afternoon, the Union troops returned to Fredericktown. The Union forces reported seven soldiers killed and some sixty wounded. The next morning, Union soldiers reported burying 160 Confederate dead, although Gen. Thompson put the number of` Confederate dead at twenty with thirty captured.

Thompson made good his retreat, carrying away about 18,000 pounds of lead taken from Mine La Motte just north of Fredericktown to aid the Confederacy. During the disorder which followed, as Union forces look possession of Fredericktown, the town was fired and several houses were destroyed. A reenactment of the Battle of` Fredericktown is now held every other year during September.