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Commanded by General Joseph Edward Johnston
After the Battle of Manassas (Bull Run) on July 21 Johnston took command of the Army of the Potomac, merging his Army of the Shenandoah into it. The units of the original Army of the Potomac under General Beauregard were designated the First Corps. However, there were no other corps yet, and the corps orginazation would not be authorized under Confederate law until late 1862. Beauregard was second in command of the army as well as commander of its only corps, but his desire to regain an independent command would be an ongoing problem until he was transferred in March.
First Corps – General Pierre Gustave Toutant Beauregard
| First Brigade | Brigadier General Milledge L. Bonham | |
| 2nd South Carolina Infantry Regiment | Colonel Joseph B. Kershaw | |
| 3rd South Carolina Infantry Regiment | Colonel James H. Williams | |
| 7th South Carolina Infantry Regiment | Colonel Thomas G. Bacon | |
| 8th South Carolina Infantry Regiment | Colonel Ellerbe Boggan Crawford Cash | |
| Boykin’s (SC) Mounted Rangers | Captain Alexander H. Boykin | |
| Alexandria (Va.) Battery | Captain Delaware Kemper | |
| 30th Virginia Cavalry, Cos. A,C,D,G,H & I | Colonel R.C.W. Radford | |
| Second Brigade | Brigadier General Richard S. Ewell | |
| 5th Alabama Infantry Regiment | Colonel Robert E. Rodes | |
| 6th Alabama Infantry Regiment | Colonel John J. Seibels | |
| 12th Alabama Infantry Regiment | Lieutenant Colonel Theodore O’Hara | |
| 12th Mississippi Infantry Regiment | Colonel Isaac G. Seymour | |
| Washington Artillery, 1st Company | Captain Thomas L. Rosser | |
| Cavalry Battalion (Goochland Light Dragoons and Governor’s Mounted Guards) | Lieutenant Colonel Wiliam H. Jenifer | to 4th VA Cav. 9/4 |
| Third Brigade | Brigadier General David R. Jones | |
| 4th South Carolina Infantry Regiment | Colonel J.B.E. Sloan | |
| 5th South Carolina Infantry Regiment | Colonel Micah Jenkins | |
| 6th South Carolina Infantry Regiment | Colonel Charles S. Winder | |
| 9th South Carolina Infantry Regiment | Colonel James D. Blanding | |
| Washington Artillery, 2nd Company | Captain Merrit B. Miller | |
| Fourth Brigade | Brigadier General James Longstreet | |
| 1st Virginia Infantry Regiment | Colonel Patrick T. Moore | |
| 7th Virginia Infantry Regiment | Colonel James L. Kemper | |
| 11th Virginia Infantry Regiment | Colonel Samuel Garland | |
| 17th Virginia Infantry Regiment | Colonel Montgomery D. Corse | |
| 30th Virginia Cavalry, Cos. B,E,F & K | Lieutenant Colonel Thomas T. Munford | |
| Washington Artillery, 3rd Company | Lieutenant John J. Garnett | |
| Loudon (Va.) Battery | Captain Arthur L. Rogers | |
| 1st Company Richmond Howitzers | Captain John C. Shields | to 7th Brig. 8/9 |
| Fifth Brigade | Colonel Philip St. George Cocke | |
| 18th Virginia Infantry Regiment | Colonel Robert E. Withers | |
| 19th Virginia Infantry Regiment | Lieutenant Colonel John B. Strange | |
| 28th Virginia Infantry Regiment | Colonel Robert T. Preston | |
| 49th Virginia Infantry Regiment | Colonel William Smith | |
| Lynchburg (Va.) Artillery | Captain H. G. Latham | |
| Sixth Brigade | Colonel Jubal A. Early | |
| 5th North Carolina State Troops | Colonel Duncan McRae | from 4th Brig. 7/24 |
| 11th North Carolina Volunteers | Colonel Wiliam W. Kirkland | from 1st Brig. 7/25 |
| 13th North Carolina Volunteers | Colonel John Franklin Hoke | |
| 24th Virginia Infantry Regiment | Colonel Peter Hairston | |
| 1st Company Fluvanna Artillery | Captain W.H. Holman | |
| Washington Artillery, 4th Company | Lieutenant Charles W. Squire | |
| Seventh Brigade | Colonel Nathan G. Evans | |
| 13th Mississippi Infantry Regiment | Colonel William Barksdale | |
| 17th Mississippi Infantry Regiment | Colonel Winfirld S. Featherston | |
| 18th Mississippi Infantry Regiment | Colonel Erasmus R. Burt | |
| 1st Company Richmond Howitzers | Captain John C. Shields | from 4th Brig. 8/9 |
| Eighth Brigade | Colonel Isaac. G. Seymour | |
| 6th Louisiana Infantry Regiment | Lieutenant Colonel Louis Lay | |
| 7th Louisiana Infantry Regiment | Colonel Harry T. Hays | |
| 8th Louisiana Infantry Regiment | Colonel Henry B. Kelly | |
| 9th Louisiana Infantry Regiment | Colonel Richard Taylor | from unattached |
| Unattached | ||
| 2nd Louisiana Battalion | Lieutenant Colonel Charles de Choiseul | |
| Leesburg Virginia Command | Brigadier General Theophilus Holmes | |
| 8th Virginia Infantry Regiment | Colonel Eppa Hunton | |
| Hampton’s (S.C.) Legion | Captain James Conner |
The brigades of Johnston’s Army of the Shenandoah were merged with Beauregard’s command after July 22.
| Jackson’s Brigade | Brigadier General Thomas J. Jackson | |
| 2nd Virginia Infantry Regiment | Colonel James W. Allen | |
| 4th Virginia Infantry Regiment | Colonel James F. Preston | |
| 5th Virginia Infantry Regiment | Colonel Kenton Harper | |
| 27th Virginia Infantry Regiment | Lieutenant Colonel J. Echols | |
| 33rd Virginia Infantry Regiment | Colonel Arthur C. Cummings | |
| 1st Rockbridge Artillery | Captain William Nelson Pendleton | |
| S. Jones’ (Bartow’s) Brigade | Brigadier General Samuel Jones | |
| 7th Georgia Infantry Regiment | Colonel Lucius Jeremiah Gartrell | |
| 8th Georgia Infantry Regiment | Lieutenant Colonel William M. Gardener | |
| 9th Georgia Infantry Regiment | Colonel Edwin R. Goulding | |
| 11th Georgia Infantry Regiment | Colonel George T. Anderson | |
| 1st Kentucky Infantry Battalion | Lieutenant Colonel H. Blanton Duncan | |
| 2nd Kentucky Battalion Sharpshooters | Major J.D. Pope | |
| Wise (VA) Artillery Battery | Captain Ephraim G. Alburtis First Lieutenant J. Pelham |
|
| Whiting’s (Bee’s) Brigade | Brigadier General William H.C. Whiting | |
| 4th Alabama Infantry Regiment | Captain Thomas Goldsby | |
| 2nd Mississippi Infantry Regiment | Colonel William C. Falkner | |
| 11th Mississippi Infantry Regiment | Colonel William H. Moore | |
| 1st Tennessee Infantry Regiment | Colonel Peter Turney | |
| 6th North Carolina Infantry Regiment | Colonel C.F. Fisher | |
| Staunton (VA) Artillery | Captain John D. Imboden | |
| Elzey’s Brigade | Colonel Arnold Elzey |
|
| 1st Maryland Infantry | Lieutenant Colonel George H. Steuart (to 7/21) Brigadier General Arnold Elzey (^ 7/21) |
|
| Third Tennessee Infantry Regiment | Colonel John C. Vaughn | |
| 10th Virginia Infantry Regiment | Colonel Simeon B. Gibbons | |
| 13th Virginia Infantry Regiment | Colonel Arthur Powell Hill | |
| Newtown Artillery | First Lieutenant R.F. Beckham | |
| Smith’s Brigade | Colonel John Horace Forney |
|
| 9th Alabama Infantry Regiment | Colonel Cadmus M. Wilcox | |
| 10th Alabama Infantry Regiment | Lieutenant Colonel James Benson Martin | |
| 11th Alabama Infantry Regiment | Colonel Sydenham Moore | |
| 19th Mississippi Infantry Regiment | Colonel C.H. Mott | |
| 38th Virginia Infantry Regiment | Colonel E.C. Edmonds | |
| Thomas (VA) Artillery | Captain P.B. Stanard | |
| Unattached | ||
| 1st Virginia Cavalry Regiment | Colonel J.H. Drake Colonel James Ewell Brown Stuart |
|
| 7th Virginia Cavalry Regiment | Colonel Angus W. McDonald |
OFFICIAL RECORDS: Series 1, vol 2, Part 1 pp. 999-1000