I have finished revising the Chickamauga Order of Battle, thanks in large part to the release of the book Maps of Chickamauga. The book contains a complete Order of Battle, including regimental strengths for every regiment. I’m sure the author had access to archive reports and morning reports that I don’t. So, along with the Official Records and unit histories, a complete and accurate Order of Battle for Chickamauga can now be constructed.
After all this work on an Order of Battle, years work really, I have come to one inescapable conclusion. The Confederates did NOT outnumber the Union army at Chickamauga. At best they equaled the Union army in strength, but in most cases, they were still outnumbered.
First let me say, I can no longer look at any unit strength for a Civil War battle without asking myself “are they referring to ‘effective strength’, ‘present for duty, equipped’, or ‘present for duty strength’.” I can’t just take a single number at face value anymore. So here’s a quick rundown. For the Union, Present for Duty, Equipped (PFDE) counts just the soldiers on the firing line. It normally includes both officers and enlisted men. Present for Duty (PFD) includes everybody that actually marched into combat. It normally includes a few non-combatants such as regimental musicians, stretcher bearers, teamsters, etc. While they may not be shouldering a musket, they are just as essential to the function of the unit as those standing on the line. For the Confederates, Effective Strength (ES) counts the soldiers on the line actually firing a weapon. However, it usually does not include officers. The Confederates also used Present for Duty, with much the same definition as the Union army. In addition, I have added a definition for the Confederates called Effective Strength + (ES+). This is simply the ES plus officers, since almost every listing does indeed give the number of officers present.
Let’s look at the big numbers, PFD. On the first day of the battle, September 19th, the Army of the Cumberland had about 62,000 men in the area, not including the Chattanooga garrison and Post’s brigade detached to guard the 20th Corps wagons. It breaks down to 54,000 infantry and 8,000 cavalry. The Army of Tennessee had a total of 63,000 with 49,000 infantry and 14,000 cavalry. Only about a 1,000 man edge, and the Confederates were still outnumbered in infantry. Its entirely possible that the PFD number for the Confederates is low, since this classification requires the most guess work. Still even given that, the number wouldn’t grow too much, maybe 3-4 thousand at most.
Now let’s look at PFDE and ES+. I won’t say these two designations are an exact match. There may be a non-com file closer that the Confederates don’t count and the Union does, small things like that. However, I think they are pretty close, and the margin for error would be fairly small. Also, these numbers are much more accurate and we have many more of them in the records. At the start of the battle, the Union army had 60,000 PFDE, with 52,000 infantry and 8,000 cavalry. The Confederates had 58,000 with 45,000 infantry and 13,000 cavalry. Clearly, the Confederates have the edge in cavalry, but the Union army is still superior in infantry.
The second day of the battle is much more difficult to judge. There is much more guesswork involved, especially if you are trying to figure out how many casualties a unit took on the first day of the battle, but you only have casualties available for the whole battle and no breakdown day by day. Still, the records are more complete than you might think. Even with Confederate reinforcements arriving on the night of the 19th, they only enjoyed a small margin of numerical superiority with 57,000 vs. 53,000 PFD. However, almost all of that was cavalry. For infantry it was about even with the Union enjoying a slight edge: 45,000 Union vs. 44,000 Confederates. The PFDE vs. ES+ infantry disparity is even greater, with the Union having 44,000 PFDE and the Confederates 41,000 ES+.
So in conclusion, if the numbers are off and you increase the Confederate totals a little, at best they are only going to break even. The only way you can get the Confederates to have a clear numerical superiority is if you add together all the Confederate units in the campaign, including those still in transit, and add them all together as they stood for the evening of the 19th. That number would put approximately 62,000 PFD Union soldiers against 68,000 Confederates, maybe 72,000+ if you included the four brigades in Hood and McLaw’s Divisions that did not make it in time for the battle. It appears as if the Union Army actually outnumbered the Confederates in most cases, especially where they faced each other rifle to rifle and you only count those units immediately available for battle.