Union Forces Commanded by Col. J.B. Plummer and Col. William P. Carlin
Confederate Forces Commanded by Brig. Gen. M. Jeff Thompson
Conclusion: Union Victory
In October, Brig. Gen. M. Jeff Thompson led a force of 3,000 men into Southeast Missouri. On October 15, he led a Confederate 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.
Two Union columns, one under Col. J.B. Plummer and another under Col. William P. Carlin, advanced on Fredericktown to overtake Thompson and his men.
On the morning of October 21, Thompson's force left Fredericktown headed south. About 12 miles out, Thompson left his supply train in a secure position and returned toward Fredericktown. He then learned that Union forces had occupied Fredericktown, so Thompson spent the morning attempting to discern the Union numbers and disposition. Unable to do so, he attacked anyway, around noon.
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 the 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, in the afternoon, 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 17th Iowa Regiment charged upon the Confederate battery, capturing 1 gun. The running battle lasted over 4 hours with the Confederates in halting retreat. Late in the afternoon, the Union troops returned to Fredericktown.
The Union occupation of Fredericktown cemented their control of southeastern Missouri.