Brigadier General W. T. Sherman's brigade.-9th and 14th regiments Massachusetts volunteers, DeKalb regiment New York volunteers, 4th regiment Michigan volunteers, Hamilton's battery, (E,) 3d United States artillery, and company I, 2d United States cavalry.

Brigadier General Kearney's brigade.-1st, 2d, and 3d regiments New Jersey volunteers, Green's battery, (G,) 2d United States artillery, and company G, 2d United States cavalry.

Brigadier General Hooker's brigade.-1st and 11th regiments Massachusetts volunteers, 2d regiment New Hampshire volunteers, and 26th regiment Pennsylvania volunteers.

Colonel Keys's brigade.—22d, 24th, and 30th regiments New York volunteers, and 14th regiment New York State militia.

Brigadier General Franklin's brigade.-15th, 18th, 31st, and 32d regiments New York volunteers, Platt's battery, (M,) 2d United States artillery, and company C, New York (Lincoln) cavalry.

Colonel Blenker's brigade.-8th and 27th regiments New York volunteers, 27th regiment Pennsylvania volunteers, and Garibaldi guard, New York vol

unteers.

Colonel Richardson's brigade.—12th regiment New York volunteers, and 2d and 3d regiments Michigan volunteers.

Brigadier General Stone's brigade.-34th and Tammany regiments New York volunteers, 1st regiment Minnesota volunteers, and 2d regiment New York State militia.

Colonel William F. Smith's brigade.—2d and 3d regiments Vermont volunteers, 6th regiment Maine volunteers, 33d regiment New York volunteers, company H, 2d United States cavalry, and Captain Mott's New York battery.

Colonel Couch's brigade.—2d regiment Rhode Island volunteers, 7th and 10th regiments Massachusetts volunteers, and 36th regiment New York volunteers. The 2d regiment Maine, the 2d regiment Wisconsin, and the 13th regiment New York volunteers, stationed at Fort Corcoran.

The 21st regiment New York volunteers, stationed at Fort Runyon.
The 17th regiment New York volunteers, stationed at Fort Ellsworth.

By October the new levies had arrived in sufficient numbers, and the process of organization so far carried on that the construction of divisions had been effected.

The following statement exhibits the composition of the army, October 15,

1861.

Organization of the army of the Potomac, October 15, 1861.

1. Brigadier General George Stoneman's cavalry command.-5th United States cavalry, 4th Pennsylvania cavalry, Oneida cavalry, (one company,) 11th Pennsylvania cavalry, (Harlan's,) and Barker's Illinois cavalry, (one company.) 2. Colonel H. J. Hunt's artillery reserve.-Batteries L, A, and B, 2d United States artillery, batteries K and F, 3d United States artillery, battery K, 4th United States artillery, battery H, 1st United States artillery, and battery A, 5th United States artillery.

3. CITY GUARD, BRIGADIER GENERAL ANDREW PORrter.

Cavalry.-Companies A and E, 4th United States cavalry.
Artillery.-Battery K, 5th United States artillery.

Infantry.-2d and 3d battalions United States infantry, 8th and 1st companies United States infantry, and Sturgis's rifles, (Illinois volunteers.)

4. BANKS'S DIVISION.

Cavalry-Four companies 3d regiment New York cavalry, (Van Allen's.) Artillery-Best's battery E, 4th United States artillery, detachment 9th New York artillery, Matthews's battery E, 1st Pennsylvania artillery, Tompkins's battery A, 1st Rhode Island artillery.

Infantry.-Abercrombie's brigade: 12th Massachusetts, 12th and 16th Indiana, and 30th Pennsylvania volunteers. Stiles's brigade: 3d Wisconsin, 29th Pennsylvania, and 13th Massachusetts volunteers, and 9th New York State militia. Gordon's brigade: 2d Massachusetts, 28th and 19th New York, 5th Connecticut, 46th and 28th Pennsylvania, and 1st Maryland volunteers.

M'DOWELL'S DIVISION.

Cavalry.-2d New York cavalry, (Harris's Light,) Colonel Davis. Artillery-Battery M, 2d, and battery G, 1st United States artillery. Infantry-Keys's brigade: 14th New York State militia, and 22d, 24th, and 30th New York volunteers. Wadsworth's brigade: 12th, 21st, 23d, and 35th New York volunteers. King's brigade: 2d, 6th, and 7th Wisconsin, and 19th Indiana volunteers.

HEINTZELMAN'S DIVISION.

Cavalry.-1st New Jersey cavalry, Colonel Halsted.
Artillery. Thompson's battery, C, United States artillery.

Infantry.-Richardson's brigade: 2d, 3d, and 5th Michigan, and 37th New York volunteers. Sedgwick's brigade: 3d and 4th Maine, and 38th and 40th New York volunteers. Jameson's brigade: 32d, 63d, 61st, and 45th Pennsylvania volunteers, and Wild Cat reserves, (Pennsylvania volunteers.)

F. J. PORTER'S DIVISION.

Cavalry.-3d Pennsylvania cavalry, Colonel Averill, and 8th Pennsylvania cavalry, Colonel Gregg.

Artillery-Battery E, 2d, and battery *E, 3d United States artillery. Infantry.-Morell's brigade: 33d Pennsylvania, 4th Michigan, 9th Massachusetts, and 4th New York volunteers. Martindale's brigade: 13th New York, 2d Maine, and 18th Massachusetts volunteers, and DeKalb regiment New York volunteers. Butterfield's brigade: 50th New York, 83d Pennsylvania, (Colonel McLean,) 17th and 25th New York volunteers, and Stockton's independent Michigan regiment.

FRANKLIN'S DIVISION.

Cavalry.-1st New York cavalry, Colonel McReynolds.

Artillery-Batteries D and G, 2d United States artillery, and Hexamer's battery, (New Jersey volunteers.)

Infantry.-Kearney's brigade: 1st, 2d, 3d, and 4th New Jersey volunteers. Slocum's brigade: 16th, 26th, and 27th New York, and 6th Maine volunteers Newton's brigade: 15th, 18th, 31st, and 32d New York volunteers.

STONE'S DIVISION.

Cavalry. Six companies 3d New York (Van Allen) cavalry.

Artillery.-Kirby's battery I, 1st United States, Vaughn's battery B, 1st Rhode Island artillery, and Bunting's 6th New York independent battery. Infantry.-Gorman's brigade: 2d New York State militia, 1st Minnesota

*This battery was transferred to Sherman's expedition.

15th Massachusetts, and 34th New York volunteers, and Tammany regiment' (New York volunteers.) Lander's brigade: 19th and 20th Massachusetts, and 7th Michigan volunteers, and a company of Massachusetts sharpshooters. Baker's brigade: Pennsylvania volunteers, (1st, 2d, and 3d California.)

BUELL'S DIVISION.

Artillery-Batteries D and H, 1st Pennsylvania artillery.

Infantry-Couch's brigade: 2d Rhode Island, 7th and 10th Massachusetts, and 36th New York volunteers. Graham's brigade: 23d and 31st Pennsylvania, and 67th (1st Long Island) and 65th (1st United States chasseurs) New York volunteers. Peck's brigade: 13th and 21st Pennsylvania, and 62d (Anderson Zouaves) and 55th New York volunteers.

M'CALL'S DIVISION.

Cavalry-1st Pennsylvania reserve cavalry, Colonel Bayard.

Artillery.-Easton's battery A, Cooper's battery B, and Kein's battery G, 1st Pennsylvania artillery.

brigade 5th, 1st, and brigade 10th, 6th, 9th, and 12th

Infantry. Meade's brigade: 1st rifles Pennsylvania reserves, 4th, 3d, 7th, 11th, and 2d Pennsylvania reserve infantry. 8th Pennsylvania reserve infantry. Pennsylvania reserve infantry.

HOOKER'S DIVISION.

Cavalry.-Eight companies 3d Indiana cavalry, Lieutenant Colonel Carter. Artillery.-Elder's battery E, 1st United States artillery.

Infantry.

:

brigade 1st and 11th Massachusetts, 2d New Hampshire, 26th Pennsylvania, and 1st Michigan volunteers. Sickles's brigade: 1st, 2d, 3d, 4th, and 5th regiments Excelsior brigade, New York volunteers.

BLENKER'S BRIGADE.

Cavalry. 4th New York cavalry, (mounted rifles,) Colonel Dickel.
Artillery-One battery.

Infantry.-Sth and 29th New York, 27th and 35th Pennsylvania volunteers, Garibaldi guard and Cameron rifles, (New York volunteers.)

SMITH'S DIVISION.

Cavalry-5th Pennsylvania cavalry, (Cameron dragoons,) Colonel Friedman. Artillery.-Ayres's battery F, 5th United States artillery, Mott's 2d New York independent battery, and Barr's battery E, 1st Pennsylvania artillery. Infantry. brigade: 2d, 3d, 4th, and 5th Vermont volunteers. Stevens's brigade: 35th and 49th New York and 6th Maine volunteers, and *79th New York State militia. Hancock's brigade: *47th and 49th Pennsylvania, 43d New York, and 5th Wisconsin volunteers. Companies B and E, Berden's sharpshooters.

Casey's provisional brigades.—5th, 6th, and 7th New Jersey volunteers, *Round-Head regiment, (Pennsylvania volunteers,) battalion District of Columbia volunteers, 40th Pennsylvania, 8th New Jersey, and 4th New Hampshire volunteers.

*The 79th New York State militia, the 47th Pennsylvania volunteers, and the Round-Head regiment, were transferred to General Sherman's expedition.

5. Garrison of Alexandria-Brigadier General Montgomery, military govCameron guard, (Pennsylvania volunteers.)

ernor.

Garrison of Fort Albany.-14th Massachusetts volunteers.

Garrison of Fort Richardson.-4th Connecticut volunteers.

Garrison of Fort Washington.-Company D, 1st United States artillery, companies H and I, 37th New York volunteers, and United States recruits unassigned.

6. DIX'S DIVISION, BALTIMORE.

Cavalry.-Company of Pennsylvania cavalry.

Artillery-Battery I, 2d United States artillery, 2d Massachusetts light battery, and a battery of New York artillery.

Infantry.-3d, 4th, and 5th New York, 17th and 25th Massachusetts, 21st Indiana, 6th Michigan, 4th Wisconsin, 7th Maine, 2d Maryland battalion, and Reading city guard, volunteers.

On the 8th of March, 1862, the President directed, by the following order, the organization of the active portion of the army of the Potomac into four army corps, and the formation of a fifth corps from the division of Banks and Shields.

The following is the text of the President's order :

"[President's General War Order No. 2.]

"EXECUTIVE MANSION,

66

Washington, March 8, 1862. "Ordered, 1st. That the major general commanding the army of the Potomac proceed forthwith to organize that part of the said army destined to enter upon active operations, (including the reserve, but excluding the troops to be left in the fortifications about Washington,) into four army corps, to be commanded according to seniority of rank, as follows:

"First corps to consist of four divisions, and to be commanded by Major General I. McDowell. Second corps to consist of three divisions, and to be commanded by Brigadier General E. V. Sumner. Third corps to consist of three divisions, and to be commanded by Brigadier General S. P. Heintzelman. Fourth corps to consist of three divisions, and to be commanded by Brigadier General E. D. Keyes.

"2. That the divisions now commanded by the officers above assigned to the commands of army corps shall be embraced in and form part of their respective corps.

"3. The forces left for the defence of Washington will be placed in command of Brigadier General James Wadsworth, who shall also be military governor of the District of Columbia.

"4. That this order be executed with such promptness and despatch as not to delay the commencement of the operations already directed to be undertaken by the army of the Potomac.

"5. A fifth army corps, to be commanded by Major General N. P. Banks, will be formed from his own and General Shields's (late General Lander's) division. "ABRAHAM LINCOLN.”

The following order, which was made as soon as circumstances permitted, exhibits the steps taken to carry out the requirements of the President's war order No. 2:

H. Ex. Doc. 15

GENERAL ORDERS No. 151.]

"ARMY CORPS.

"HEADQUARTers Army of the Potomac,

"Fairfax Court-house, Virginia, March 13, 1862.

"In compliance with the President's war order No. 2, of March 8, 1862, the active portion of the army of the Potomac is formed into army corps, as follows: First corps, Major General Irwin McDowell, to consist for the present of the divisions of Franklin, McCall, and King. Second corps, Brigadier General E. V. Sumner; divisions, Richardson, Blenker, and Sedgwick. Third corps, Brigadier General S. P. Heintzelman; divisions, F. J. Porter, Hooker, and Hamilton. Fourth corps, Brigadier General E. D. Keyes; divisions, Couch, Smith, and Casey. Fifth corps, Major General N. P. Banks; divisions, Williams and Shields.

"The cavalry regiments attached to divisions will, for the present, remain so. Subsequent orders will provide for these regiments, as well as for the reserve artillery. Regular infantry and regular cavalry arrangements will be made to unite the divisions of each army corps as promptly as possible.

"The commanders of divisions will at once report in person, or where that is impossible, by letter, to the commander of their army corps. "By command of Major General McClellan.

"A. V. COLBURN, "Assistant Adjutant General.”

I add a statement of the organization and composition of the troops on April 1, commencing with the portion of the army of the Potomac which went to the Peninsula, giving afterwards the regiments and batteries left on the Potomac, and in Maryland and Virginia after April 1, 1862.

Troops of the army of the Potomac sent to the Peninsula in March and early in April, 1862..

1st. Cavalry reserve, Brigadier General P. St. G. Cooke.-Emery's brigade: 5th United States cavalry; 6th United States cavalry; 6th Pennsylvania cavalry. Blake's brigade: 1st United States cavalry; 8th Pennsylvania cavalry; Barker's squadron Illinois cavalry.

2d. Artillery reserve, Colonel Henry J. Hunt: Graham's battery K and G, 1st United States, 6 Napoleon guns; Randall's battery E, 1st United States, 6 Napoleon guns; Carlisle's battery E, 2d United States, 6 20-pounder Parrott guns; Robertson's battery, 2d United States, 6 3-inch ordnance guns; Benson's battery M, 2d United States, 6 3-inch ordnance guns; Tidball's battery A, 2d United States, 6 3-inch ordnance guns; Edwards's battery L and M, 3d United States, 6 10-pounder Parrott guns; Gibson's battery C and G, 3d United States, 6 3-inch ordnance guns; Livingston's battery F and K, 3d United States, 4 10-pounder Parrott guns; Howe's battery G, 4th United States, 6 Napoleon guns; De Russy's battery K, 4th United States, 6 Napoleon guns; Weed's battery I, 5th United States, 6 3-inch ordnance guns; Smead's battery K, 5th United States, 4 Napoleon guns; Ames's battery A, 5th United States, 6-4 10-pounder Parrott and 2 Napoleon-guns; Diedrick's battery A, New York artillery and battalion, 6 20-pounder Parrott guns; Vogelie's battery B, New York artillery and battalion, 4 20-pounder Parrott guns; Knierim's battery C, New York artillery and battalion, 4 20-pounder Parrott guns; Grimm's battery D, New York artillery and battalion, 6 32-pounder howitzer guns. Total, 100

guns.