The (Re) Emergence of the First Corps Part One

Joseph Poffenberger Farm - First Corps assembly area on September 17, 1862

The Army of the Potomac adopted the corps structure on March 4, 1862 despite the misgivings of George McClellan (USMA 1846). He would have preferred to develop corps commanders based upon proven merit and experience in the field.  To make matters worse, seniority alone was the criteria for determining the first five corps commanders.  The men appointed by Lincoln were:

·      First Corps Irvin McDowell (USMA 1838)

·      Second Corps Edwin Vose Sumner (direct appointment 1819)

·      Third Corps Samuel Heintzelman (USMA 1826)

·      Fourth Corps Erasmus Keyes (USMA 1832)

·      Fifth Corps Nathanial Banks (appointed 1861).

When McClellan took to the field with the Army of the Potomac, he was “temporarily” relieved of his position as General-in-Chief of the United States Army on March 11, 1862.  No replacement was immediately named leaving Army affairs in the hands of Secretary of War Edwin Stanton. 

McClellan planned for the First Corps to play a key role in his Peninsula Campaign against Richmond.  Scheduled to leave the environs of Washington after the departure of the Second, Third and Fourth corps, it was held back by the Lincoln administration when authorities decided that McClellan apparently did not leave the requisite number of troops back in the city for its defense.  Where McClellan counted Nathanial Banks Fifth Corps as part of the Washington defenses, Secretary of War Stanton did not.  Lincoln did not like McClellan’s indirect approach against Richmond. The President and Stanton particularly were concerned for the safety of the capital city. In particular they looked just now at the actions of Confederate Major General Thomas J. Jackson (USMA 1846) in the Shenandoah Valley. 

McClellan would eventually prevail upon Lincoln to send much of the First Corps to Virginia.  This corps in March of 1862 in no way resembled the organization that fought at Antietam six months later.  At this earlier date, it contained the divisions of William Franklin (USMA 1843), George McCall (USMA 1822), and Rufus King (USMA 1833). Lincoln would send McClellan both Franklin and McCall’s divisions and they would play key roles in the Peninsula campaign. Franklin’s division would form the basis of the Sixth Corps and eventually be commanded by William Slocum (USMA 1852) during the Maryland Campaign.  McCall’s Division was the Pennsylvania Reserves Division commanded at Antietam by George Meade (USMA 1835).  The departure of these two divisions left McDowell with just Rufus King’s division.

With McClellan no longer in command of the United States Army, the War Department on April 4, 1862 created two new departments west and south of the District of Columbia to address concerns for the safety of the capital. 

The Department of the Shenandoah included the Valley of Virginia and Allegheny & Washington Counties in Maryland.  Nathanial Banks commanded this Department. His Fifth Corps command also disappeared from the command structure but would reemerge on May 18, 1862 on the Peninsula as Fitz John Porters Fifth Corps. The troops of the Department were the divisions of Alpheus Williams and James Shields. 

The Department of the Rappahannock included Virginia east of the Blue Ridge and west of the Potomac River, the Fredericksburg and Richmond Railroad, including the District of Columbia and the country between the Potomac and the Patuxent Rivers.  Irvin McDowell commanded this Department.  With the siphoning off of two of his original divisions, the First Corps for a time disappeared from the Army command structure.  King’s division was designated 1^st Division, Department of the Rappahannock.  But a new division was being organized by the first week of May.