My co-authors and I have been researching to assemble an estimate of the strength of Missouri Southerners who served under arms for the South. Using minimal--meaning muster-out--strength, we came up with a downside estimate for men serving in the Missouri State Guard at 40,000 men. This easily could have gone well over 50,000, since thousands of men failed to serve their full six-month enlistment in the Guard (thousands were captured, others had their commands dispersed by Federal forces).

Probably in excess of 65,000 men from Missouri served in the Confederate forces. Probably 30,000+ formerly served in the Guard. Union occupation forces were not particularly kind to the civilians of Missouri and served as marvelous recruiting officers for the Confederacy.

If you're really wanting some hard numbers, I can search to see if I still have the analysis I did to come up with these numbers. I had a computer crash last December and lost some files, but I may still be able to find that one.