In the Humansville Cemetery, Polk County, Missouri, there is a headstone that reads:

Henry Garrison

Born
Aug. 23, 1816

Killed
Aug. 18, 1863

He lies next to his wife Mary M. Garrison b. 9/16/1828 d. 10/23/1908.

Does anyone have any information on what occurred on or about August 18, 1863, in Polk or St. Clair County in which Henry Garrison would have been killed?

Ron Garrison