Gettysburg: Union Order of Battle

Late last week, I had the chance to return to the Gettysburg battlefield on vacation. As a Civil War buff, it's a bit of pilgrimage for me over the years. As I have thought about the Union Army of the Potomac's order of battle, it seems to be quite top heavy to me in terms of number of infantry corps. Might it have made sense to reduce the number of infantry corps from 7 to 6 for the sake of efficiency when it comes to command and control?

For example, maybe given its poor performance at Chancellorsville, break up the 11th corps, with a three brigade division going to 3rd corps and another going to 12th corps? It had only 6 brigades, so it would be a likely candidate. Maybe a POD would be the loss of Oliver Howard and a division commander or two at Chancellorsville.

Granted, such a reorganization in those two short months is probably not likely, but what might have changed on the first day had those changes been implemented? I can't remember off the top of my head which corps arrived after 1st and 11th, I think it was 2nd or 3rd. How might the presence of 2nd corps or 3rd corps (reinforced) changed the outcome of day 1? Would the Union still find itself digging in on Cemetery and Culp's Hills? I do have a strong hunch that was the plan all along.

Here is an order of battle for basic reference:

http://gettysburg.stonesentinels.com/battle-of-gettysburg-facts/strength-casualties-usa/
 
Late last week, I had the chance to return to the Gettysburg battlefield on vacation. As a Civil War buff, it's a bit of pilgrimage for me over the years. As I have thought about the Union Army of the Potomac's order of battle, it seems to be quite top heavy to me in terms of number of infantry corps. Might it have made sense to reduce the number of infantry corps from 7 to 6 for the sake of efficiency when it comes to command and control?
Indeed, it would have been better to reduce it to perhaps 4 or 5 infantry Corps. Before Hooker's reign, Burnside organized the corps into 'Grand Divisions'. But this proved to be unwieldy (though Fredericksburg is not exactly a fair place to test it out). Hooker broke up the Grand Divisions, deciding that they were too unwieldy. Eventually, Meade would reduce the corps to 3 corps in the aftermath of the Mine Run campaign.
Granted, such a reorganization in those two short months is probably not likely, but what might have changed on the first day had those changes been implemented? I can't remember off the top of my head which corps arrived after 1st and 11th, I think it was 2nd or 3rd. How might the presence of 2nd corps or 3rd corps (reinforced) changed the outcome of day 1? Would the Union still find itself digging in on Cemetery and Culp's Hills? I do have a strong hunch that was the plan all along.
The corps that arrived after the I and XI Corps is the XII Corps, although the III Corps could have arrived a lot earlier if Sickles decided to march immediately when he first received Reynolds' order to march to Gettysburg. A reinforced XII Corps wouldn't have done much, considering that Slocum dithered on whether or not he should march to Gettysburg, and even then he would have arrived too late to prevent the rout of the I and XI Corps. An early arrival would at least release von Steinwehr's division from reserve on Cemetery Hill to soften impact of Jubal Early's assault and provide a large reserve for the I and XI Corps. At the very least, one division would be kept at Cemetery Hill as reserve.

An example of what I think would have been an improvement to the reduced Corps:
  • The XI Corps is a unit with morale and leadership issues, it would be better off to break it up and send its divisions to the XII and II Corps. This strengthens both Corps to 4 divisions. The only way I can think of to make this even better is to sack Slocum (XII Corps) and replace him with Alpheus Williams, who has a good appreciation for the defensive value of trenches.
  • The III Corps is also an understrength unit, containing only 2 divisions. It gets broken up too with its divisions going to the I and V Corps, bringing both Corps up to 4 divisions.
So now, we have reduced the Army of the Potomac to 5 infantry corps, strengthened to 4 divisions (except for the VI Corps). Ideally Skyes, Slocum and mediocre division commanders would be sacked, but you just can't have everything. I daresay that this would give Lee quite a thrashing ;)
 
Late last week, I had the chance to return to the Gettysburg battlefield on vacation. As a Civil War buff, it's a bit of pilgrimage for me over the years. As I have thought about the Union Army of the Potomac's order of battle, it seems to be quite top heavy to me in terms of number of infantry corps. Might it have made sense to reduce the number of infantry corps from 7 to 6 for the sake of efficiency when it comes to command and control?

For example, maybe given its poor performance at Chancellorsville, break up the 11th corps, with a three brigade division going to 3rd corps and another going to 12th corps? It had only 6 brigades, so it would be a likely candidate. Maybe a POD would be the loss of Oliver Howard and a division commander or two at Chancellorsville.

Granted, such a reorganization in those two short months is probably not likely, but what might have changed on the first day had those changes been implemented? I can't remember off the top of my head which corps arrived after 1st and 11th, I think it was 2nd or 3rd. How might the presence of 2nd corps or 3rd corps (reinforced) changed the outcome of day 1? Would the Union still find itself digging in on Cemetery and Culp's Hills? I do have a strong hunch that was the plan all along.

Here is an order of battle for basic reference:

http://gettysburg.stonesentinels.com/battle-of-gettysburg-facts/strength-casualties-usa/

I"ll get back to you...
 
This is one of those things that is heavily influenced by political considerations, which has a lot to do with why it took so long to reorganize the Army of the Potomac even after Gettysburg. A lack of standardization across the entire army did have the effect of weakening every piece of it. You don't just have Corps with completely different compositions all over the place, every division and every brigade could widely vary in manpower and experience. This is partially informed by a regimental system that tended to just create new regiments rather than reinforcing them with replacements.

I suspect that there would be some tactical utility to rationalizing the various corps with an eye towards phasing a few out, but there's also a timeline issue here. Meade only takes command on June 28th. Hooker is a lame duck after Chancellorsville. Unlikely that this kind of far reaching organization could fluidly occur in an army on the march responding to an emergency even if political considerations are left to the side.
 
Top