Battle of Fredericktown The Battle of Fredericktown was an engagement of the American Civil War . It took place on October 21 , 1861 , in Madison County , Missouri . Union victory consolidated their control of southeastern Missouri . Background . In October 1861 , Missouri State Guard Brig . Gen . M . Jeff Thompson led a 1500 - man force into southeastern Missouri . On October 15 , he burned the Iron Mountain Railroad bridge over the Big River in Jefferson County , capturing many of the bridge guards . Two Union columns , one under Col . Joseph B . Plummer with 1 , 500 men and another under Col . William P . Carlin with 3 , 000 men , were sent in pursuit . By October 20 , Thompson had learned of the Union pursuit and withdrew south of Fredericktown . That evening , however , he decided to attack the Federal advance with his infantrymen . Battle . Thompson spent the early morning hours trying to determine the enemy ' s numbers and disposition . Unable to do so , he placed his troops and artillery in ambush along the road and awaited the Union forces . The bulk of the Missouri State Guard force was hidden from view on wooded high ground that formed a U overlooking the road . Forward of the main body , Col . Aden Lowe ' s infantry regiment waited in a cornfield as bait . Close behind was a supporting 12 - pounder cannon as well as three 6 - pounders farther to the rear and flank . About noon Plummer arrived with his column and a detachment of Col . William P . Carlin ' s troops . Capt . Stewart ' s Illinois cavalry company made the initial contact . Col . Ross ' s 17th Illinois infantry engaged Lowe ' s troops first with skirmishers , then the main line of the regiment . A section of Union artillery was brought into service against the Missourians ' 12 - pounder , which responded . The 20th Illinois and 11th Missouri ( Union ) applied pressure to both flanks of Lowes ' s force as more Union artillery joined the battle . Lowe , having waited too long to disengage , was killed by a shot to the head , and his regiment retreated taking heavy casualties . The 1st Indiana Cavalry attempted to pursue and to capture the exposed 12 - pounder , but were stopped with heavy casualties by the fire of Thompson ' s forces on both ridges . They called for infantry support and the 17th Illinois surged forward to claim the now abandoned piece . As more Union infantry poured onto the field , Thompson began an orderly withdrawal of the guardsmen . In this he mostly succeeded , except for some routing cavalry . Casualties and aftermath . Thompson ' s Missouri State Guardsmen suffered a total of 145 casualties during the battle , including 25 dead , 40 wounded , and 80 captured . They also lost one artillery piece , an old iron 12 - pounder . Union casualties were reported as 7 killed and about 60 wounded . There were a number of other casualties ( primarily Union ) in skirmishes before and after the battle . Some of the Union soldiers believed that locals had assisted Thompson in the engagement . They were also angered by perceived mistreatment of Unionist citizens along the line of march . This resentment led to retaliation against the town by the rank and file . At least seven homes in Fredericktown were burned and other buildings damaged before the officers regained control of their men .