United States Army


< to July • August 1861

Commanded by Brigadier General Irvin McDowell

The Department was discontinued and merged into the Department of the Potomac on August 17, 1861

1st Division

Brigadier General Daniel Tyler
First Brigade Colonel Erasmus Keyes
2nd Maine Infantry Regiment Colonel Charles D. Jameson  to Potomac, Fort Corcoran
2nd Connecticut Infantry Regiment Colonel A. H. Terry  mustered out 8/7
3rd Connecticut Infantry Regiment Colonel J. Chatfield  mustered out 8/12
Second Brigade Brigadier General Robert C. Schenck
2nd New York State Militia Colonel G. W. B. Tompkins to Potomac, Stone’s Brig.
New York Artillery, Battery B Captain Thaddeus P. Mott to Potomac, Smith’s Brig.
2nd United States Artillery, Battery E Captain Carlisle to Dept. Potomac
Third Brigade Colonel W. T. Sherman
13th New York Infantry Regiment Colonel Isaac F. Quinby  to Potomac, Fort Corcoran
79th New York Infantry Regiment Lieutenant Colonel S.M. Elliott  to Potomac, Smith’s Brig.
2nd Wisconsin Infantry Regiment Colonel P. S. Coon  to Potomac, Fort Corcoran
3rd United States Artillery, Battery E Captain Ayers  to Dept. Potomac, Sherman’s Brig.
Fourth Brigade Colonel Israel Richardson
1st Massachusetts Infantry Regiment Colonel R. Cowdin  to Dept. Potomac, Hooker’s Brig.
12th New York Infantry Regiment Colonel E. L. Walrath  to Dept. Potomac, Richardson’s Brig.
2nd Michigan Infantry Regiment Major A. W. Williams  to Dept. Potomac, Richardson’s Brig.
3rd Michigan Infantry Regiment Colonel D. McConnel  to Dept. Potomac, Richardson’s Brig.
1st United States Artillery, Battery G Lieutenant J. Edwards  to Dept. Potomac, Richardson’s Brig.
2nd United States Artillery, Battery M Captain H. J. Hunt  to Dept. Potomac, Franklin’s Brig.

2nd Division

Colonel David Hunter
First Brigade Colonel Andrew Porter
14th New York State Militia Lieutenant Colonel Edward B. Fowler  to Keyes’ Brig. Dept. Potomac
27th New York Infantry Regiment Major Joseph J. Bartlett to Heintzleman’s Brig. Dept. Potomac
35th New York Infantry Regiment Colonel A. M. Wood to Hunter’s Brig. Div. Potomac
2nd United States Infantry, Cos. C & K
3rd U.S., Cos. B, D, G, H & K
8th U. S., Co. G
Major George Sykes
1st United States Cavalry, Cos. A & E
2nd U. S. Dragoons, Co. K
2nd U. S. Cavalry, Cos. B, E, G & I
Major Innis N. Palmer  to Cavalry Reserve, Div. Potomac
United States Marine Battalion Major J. G. Reynolds  to U.S. Navy
Second Brigade Colonel Ambrose Burnside
2nd New Hampshire Infantry Regiment Lieutenant Colonel Frank S. Fiske  to Hooker’s Brig.., Div. Potomac
2nd Rhode Island Infantry Regiment Lieutenant Colonel F. Wheaton  to Couch’s Brig., Div. Potomac
1st Rhode Island Artillery, Battery A Captain William H. Reynolds  Assigned to Dept. of the Shenandoah

3rd Division

Colonel Samuel P. Heintzelman
First Brigade Colonel W. B. Franklin
11th Massachusetts Infantry Regiment Colonel G. Clark to Hooker’s Brig., Div. Potomac
1st Minnesota Infantry Regiment Colonel W. A. Gorman to Stone’s Brig., Div. Potomac
1st United States Artillery, Battery I Lieutenant E. Kirby to Stone’s Brig., Div. Potomac
Second Brigade Colonel J. H. Hobart Ward
11th New York Infantry Regiment Lieutenant Colonel John A. Cregier  to New York City
38th New York Infantry Regiment Lieutenant Colonel Addison Farnsworth  to Howard’s Brig., Div. Potomac 8/4
1st Michigan Infantry Regiment Major A. F. Bidwell  muster out
4th Michigan Infantry Regiment Colonel D. A. Woodbury  to Sherman’s Brig., Div. Potomac
2nd United States Artillery, Battery D Captain R. Arnold  to Kearney’s Brig., Div. Potomac
Third Brigade Colonel Oliver O. Howard
3rd Maine Infantry Regiment Major H. G. Staples  to Howard’s Brig., Div. Potomac
4th Maine Infantry Regiment Colonel H. G. Berry  to Howard’s Brig., Div. Potomac
5th Maine Infantry Regiment Colonel M. H. Dunnell  to Heintzleman’s Brig., Div. Potomac
2nd Vermont Infantry Regiment Colonel H. Whiting  to Smith’s Brig., Div. Potomac

4th Division

Brigadier General Theodore Runyon
First Brigade
1st New Jersey State Militia Colonel Adolphus J. Johnson Mustered out 7/31
2nd New Jersey State Militia Colonel Henry M. Baker Mustered out 7/31
3rd New Jersey State Militia Colonel William Napton Mustered out 7/31
4th New Jersey State Militia Colonel Matthew Miller, Jr. Mustered out 7/31
Second Brigade
1st New Jersey Infantry Regiment Colonel William R. Montgomery to Potomac – Kearney’s Brig.
2nd New Jersey Infantry Regiment Colonel George W. McLean to Potomac – Kearney’s Brig.
3rd New Jersey Infantry Regiment Colonel George W. Taylor to Potomac – Kearney’s Brig.
41st New York Infantry Regiment Colonel Leopold Von Gilsa to Potomac – Sherman’s Brig.

5th Division

Colonel Dixon S. Miles
First Brigade Colonel Louis Blenker
8th New York Infantry Regiment Lieutenant Colonel J. Stahel to Blenker’s Brig., Div. Potomac
29th New York Infantry Regiment Colonel Adolph Von Steinwehr to Blenker’s Brig., Div. Potomac
39th New York Infantry Regiment Colonel Frederick G. D’Utassy to Blenker’s Brig., Div. Potomac
27th Pennsylvania Infantry Regiment Colonel Max Einstein to Blenker’s Brig., Div. Potomac
2nd United States Artillery, Battery A Captain J. C. Tidball to Heintzleman’s Brig., Div. Potomac
Bookwood’s New York Battery Captain Charles Bookwood (29th NY) to Blenker’s Brig., Div. Potomac; Designated 2nd New York Battery
Second Brigade Colonel T. Davies
16th New York Infantry Regiment Lieutenant Colonel S. Marsh  to Blenker’s Brig., Div. Potomac
18th New York Infantry Regiment Colonel William A. Jackson  to Franklin’s Brig., Div. Potomac
31st New York Infantry Regiment Colonel Calvin E. Pratt  to Franklin’s Brig., Div. Potomac
32nd New York Infantry Regiment Colonel Roderick Matheson  to Franklin’s Brig., Div. Potomac
2nd United States Artillery, Battery G Lieutenant O. D. Greene  to Kearney’s Brig., Div. Potomac