For a list of Enrolled Missouri Militia units by counties of origin:
-- Kirby Ross compiled one in George and Deb Rule's excellent website www.civilwarstlouis.com and look in the table of contents.
--Another possible source for this is Tom Pearson of the St. Louis Public Library. He composed a list of EMM units and their known weapons of issue at http://previous.slpl.org/libsrc/moquartermaster.htm and he has other information about the EMM.
--About 15 years ago I recall a man called Mark ____ composed such a list online, but I haven't heard from that in years. I seem to think his surname is "Lautner" or some such. Perhaps one of the other readers will help me with that.

A word of caution. The EMM was Missouri's own emergency state army created in a hurry in the summer of 1862 when parts of Missouri were overrun by southern guerrillas and Confederate recruiters. As a result, some of the unit organizations were thrown together haphazardly. For instance, although there were regiments between the 1st and 89th in number, a bunch of numbers in between failed to come to fruition.

There was in St. Louis even a regiment or three of purely honorary members such as persons who contributed to the EMM program, contractors, and the like. Also in St. Louis the firemen and policemen were placed in one or two EMM regiments more or less on an honorary basis because their work was needed more at the job than in battle (The state control of the St. Louis Metropolitan Police dating back to these Civil War origins is a real bone of contention in St. Louis now, by the way.). The St. Louis area regiments numbered between the 1st and about the 22nd or so.

Further, some regiments had companies in one or three counties in one part of Missouri and the rest of the regiment consisted of the other companies in another distant part of the state--split regiments, I call them. This is a real trap for an unwary researcher trying to discover about great, great grandfather.

In strongly southern parts of the state or slightly populated parts like the northern Ozarks there were EMM regiments that had a company or two in each county over a vast region, particularly in southeast and southwest Missouri.

In heavily populated areas some counties had more than one EMM regiment, too.

As if that wasn't enough to contemplate, some regiments were so poorly commanded or disciplined that they bacame an embarrassment to the program and were not activated even when trouble came to their region. They existed only on paper.

Further, some were so intimidated by local guerrillas bands and strong southern suppport that they simply ceased to exist, such as the 71st EMM in west-central Missouri. The 77th EMM in the Jackson County and Kansas City area remained inactive for most of the war for that reason.

We won't even go into the "Paw Paw" 81st and 82nd EMM Regiments of just north of Kansas City composed intentionally of companies of southerners including returned Rebel soldiers to combat the guerrillas and especially the troublesome Kansas jayhawker raids that continued throughout most of the war along the common border. The theory was that this "experiment" would work only if these guys wouldn't have to face regular Confederate troops. Most of these men refused to fire on any southern troops flying the Confederate flag. Somebody forgot to tell the Union command that many of the guerrillas in west-central Missouri served in both irregular and regular southern units at various time during the war.

That doesn't include the Provisional Enrolled Missouri Militia regiments of 1863, the home guard units of 1861, the citizen guard units or Provisional EMM companies of 1864, and other crazy categories. It is a bewildering array of different units and types of units. Don't overlook that your ancestor served in one kind during 1861, another in 1862, a third kind in 1863, and so on. Also, many Missouri men served on one side for part of the war and then the opposing side for another part of the war.

The Union EMM program of July 1862 instituted universal miltitary service in Missouri by both state and military decree, so any able-bodied man living in the state was compelled to serve. This really helped southern recruiting in Missouri that summer, too. Many guys just left the state for the mines out west or hid out in dugouts and caves near home and had the wife and kids bring their food. That last one only worked for a few weeks until autumn weather arrived.

Then again, you could place a query in this forum asking for that specific information. I would say that you will receive a good reply or two.

Bruce Nichols