"Slow Death of Attrition: The Third Corps" Topic

"Before the outbreak of the Civil War the largest standing organization of troops in the Union Army was defined by the regiment, which at full strength was usually a bit over 1000 men and officers and comprised of 10 companies. The large scale battles which became distressingly apparent following the battle of First Bull Run/ First Manassas, in July 1861, necessitated the need for larger formations of troops to combat Southern resistance. At this point, the largest of these organizations became defined by the division, which was made up of 2-6 brigades, each comprised of 2-6 regiments. By the beginning of 1862, Union officials had put in motion plans to combine 2-4 divisions into corps formation. In March of 1862, five corps were formed and eventually combined into the Army of the Potomac.

There were four U.S. Army corps designated as the Third (III) Army Corps: Three of which were extremely short lived. These were the Army of Virginia, June-September, 1862; the Army of the Ohio, September-October, 1862; and the Army of the Cumberland, October-November, 1862. Each of these short lived organizations numbered the member corps according to its own existence, a practice that was discontinued as the War moved forward and troop formations became more standardized. The 3rd Corps of the Army of the Potomac was a two year affair and one of fame and glory, as well as the topic of our discussion…"

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Armand

This is not entirely accurate.

"The year 1863 was an extremely destructive period for the 3rd Corps as it was in the very thick of the major operations of the Army of the Potomac. It started the year with over 17,000 men, including non-combatants. In each of the Battles of the Chancellorsville and Gettysburg campaigns, loses surmounted 4200 men. With continuously mounting casualties, expiring enlistments and desertion adding to the mix of depletion, the Corps was drastically being reduced despite new recruits and the addition of a third division. By the beginning of 1864, it was becoming apparent that the attrition eating away at them was curtailing the effectiveness of the organization to operate within the larger Army."

In January 1864, the Third Corps was the largest corps in the Army of the Potomac! It being broken up was strictly political and for a lack of good leaders. The didn't have a lot of experienced division and corps commanders.

Yes, I think that Meade wanted to keep the 2nd, 5th and 6th Corps because those had his best corps commanders: Hancock, Warren and Sedgwick (as opposed to Newton and French of the 1st and 3rd Corps respectively). The 3rd Corps was split up, with its 2 older divisions going to the 2nd Corps and the newer (post-Gettysburg) division going to the 6th Corps.

I don't recall the Army of the Ohio ever having numbered corps, just Left, Right and Center wings, but I might be slipping.

interesting find.

and the addition of a third division

This focuses too much on Gettysburg. Third Corps had three divisions prior to the Gettysburg campaign as well as afterwards.

Thanks.

Armand

This focuses too much on Gettysburg. Third Corps had three divisions prior to the Gettysburg campaign as well as afterwards.

Yes, but those were consolidated down to 2 divisions before G'burg, and a new 3rd Div was added after the battle (and the corps' heavy losses), namely French's troops who had been guarding the mountain passes in MD. (And that's how French became the corps commander.)

Let me approach this from a different angle.

Third Corps' two division organization at Gettysburg was an aberration. Third Corps like other corps in the Army of the Potomac had been upgraded to three divisions in 1862. It took three divisions into battle at Chancellorsville in May of 1863 before being reduced to a two division corps for Gettysburg. After Gettysburg the corps was again increased to three divisions.

According to army returns on June 30, even with two divisions, Third Corps was the fourth strongest of the Army of the Potomac's seven infantry corps. It was stronger than the three division First and Eleventh Corps, and was only slightly weaker than the three division Second and Fifth Corps. By July 4 it had slipped to fifth strongest, but it was only slightly weaker than the three division Second Corps. Third Corps was one of four corps whose strength on July 4 was less than 60% of its strength on June 30. After Gettysburg Third Corps was rebuilt. The same is also true of other Union corps at Gettysburg.

Third Corps fate was not a slow death by attrition. It was as Cleburne states the result of army politics.

Don, yes during the Perryille/Kentucky campaign Buells Army of the Ohio had corps numbered I, II, and III. I think they actually used the roman numerals in the official records and not First, Second, and Third.

Thanks also…

Armand