Sorry about the delay, but I just noticed this mention of the 17th Illinois Cavalry at Centralia on September 22. The 17th was one of the 100-day's regiments raised by Illinois that fought guerrillas in Missouri in the summer and fall of 1864. Some of these Illinois troopers were poorly armed, trained, and led, but the Union command in Missouri was desperate at that time since the Yankee setbacks in Arkansas allowed literally hundreds of guerrillas and Confederate recruiters to flood into MO, and a large number of them went to northeast Missouri.

Down to cases, Frederick Dyer's "A Compendium of the War of the Rebellion," volume 2, page 812 says only that part of the 17th Illinois Cavalry was involved in a skirmish at or near Centralia on 22 September. Typical of Dyer's landmark work, no other details are given, and he made no mention of Union casualties, although he often did if he was aware of any. I believe Dyer got his info from Union army records.

I am working on September 1864 across all of Missouri, but I haven't got to northeast MO yet, so I cannot give any corroborating information or give an estimate of who the Illinois soldiers faced at or near Centralia that day. Just off the top of my head from my August 1864 work there, it could have been one of three or four bushwhacker bands. Boone County was just about overrun with them then to the extent that the local Union EMM general was besieged in Columbia for a day or three a few weeks earlier than this. The Missouri Confederates saw Price's upcoming raid as their last big hope for MO and pulled out all the stops for much of this year. That's why Illinois sent the Yanks several regiments of newly recruited cavalry to help out. It's exciting to write about.

Bruce Nichols