Peninsula campaign order of battle: Union

The following Union Army units and commanders were the initial structure on April 4, 1862 of the Union Department of the Potomac during the Peninsula campaign of the American Civil War. This list includes units deployed to the Virginia Peninsula, and those that remained in the Washington area. The Confederate order of battle is listed separately.

Abbreviations used

Military rank

MG = Major GeneralBG = Brigadier GeneralCol = ColonelLtc = Lieutenant ColonelMaj = MajorCpt = CaptainLt = Lieutenant

Army of the Potomac

The following units were the initial organization of the Army of the Potomac on the peninsula.
MG George B. McClellan, Commanding
Headquarters and Body Guard

Co. A, 4th U.S. Cavalry: Lt James B. McIntire
Co. E, 4th U.S. Cavalry: Lt William O'Connell
Oneida Independent Cavalry Company: Cpt Daniel P. Mann
Sturges' Rifles: Cpt James Steele

Provost Guard

2nd U.S. Cavalry: Maj Alfred Pleasonton
Battalion of 8th U.S. Infantry and 17th U.S. Infantry : Maj George L. Willard

Staff

Col Randolph B. Marcy, Chief of Staff

Maj Granville O. Haller, Commandant of General Headquarters

Function	Individuals
Adjutant BG Seth Williams	Ltc James A. Hardie Cpt Richard B. Irwin
Inspector General Col Delos B. Sackett	Maj Nelson H. Davis
Engineers BG John G. Barnard	Ltc Barton S. Alexander Cpt Charles S. Stewart Lt Cyrus B. Comstock Lt Miles D. McAlester Lt William E. Merrill Lt Francis U. Farquhar
Topographical Engineers BG Andrew A. Humphreys	Lt Henry L. Abbot Lt Orlando G. Wagner Lt Nicholas Bowen Lt John Moulder Wilson Lt James H. Wilson
Medical Corps Charles S. Tripler	Surgeons and Nurses
Quartermaster Maj Stewart Van Vliet	Ltc Rufus Ingalls Ltc Charles G. Sawtelle
Commissary Col Henry F. Clarke	Col Amos Beckwith Ltc George Bell Ltc A. Parker Porter Cpt Thomas Wilson Cpt Brownell Granger Cpt William H. Bell Cpt John H. Woodward Cpt W.R. Murphy
Ordnance Cpt Charles P. Kingsbury	Lt Thomas G. Baylor Other unnamed officers
Provost-Marshal BG Andrew Porter	Maj William H. Wood Cpt James W. McMillan Cpt William T. Gentry Cpt James W. Forsyth Lt John W. Jones Lt Charles F. Trowbridge Lt Calvin D. Mehaffey
Judge Advocate Col Thomas T. Gantt	Unnamed officers
Signal Corps Maj Albert J. Myer	Unnamed officers
Telegraphic Office Maj Thomas Eckert	Mr. A. Harper Caldwell
Balloon Corps Professor Thaddeus S.C. Lowe	Lowe's Aeronauts
Personal Staff	Col Thomas M. Key Col Edward H. Wright Col John J. Astor, Jr. Ltc Albert V. Colburn Ltc Nelson B. Sweitzer Ltc Edward McK. Hudson Ltc Paul Von Radowitz Maj Herbert Von Hammerstein Maj William W. Russell Maj Ferdinand Lecompte Cpt George A. Custer Cpt Joseph Kirkland Cpt Arthur McClellan Cpt Louis Philippe d'Orleans Cpt Robert d'Orleans Cpt Martin T. McMahon Cpt William P. Mason, Jr. Cpt William F. Biddle Cpt Edward A. Raymond

II Corps

BG Edwin Sumner, Commanding
Ltc Joseph H. Taylor, Adjutant

Division	Brigade	Regiments and others
First Division BG Israel B. Richardson	First Brigade BG Oliver O. Howard	5th New Hampshire: Col Edward E. Cross 81st Pennsylvania: Col James Miller 61st New York: Col Francis C. Barlow 64th New York: Col Thomas J. Parker
First Division BG Israel B. Richardson	Second Brigade BG Thomas Francis Meagher	69th New York: Col Robert Nugent 63rd New York: Ltc John Burke 88th New York: Col Henry M. Baker
First Division BG Israel B. Richardson	Third Brigade BG William H. French	52nd New York: Col Paul Frank 57th New York: Col K. Zook 66th New York: Col Joseph C. Pinckney 53rd Pennsylvania: Col John R. Brooke
First Division BG Israel B. Richardson	Artillery	Batteries A & C, 4th U.S. Artillery: Cpt Francis N. Clarke * Six Napoleons [Battery G, 1st New York Volunteer Infantry Regiment\|1st New York Light Artillery\|Battery G, 1st New York Artillery]: Cpt John D. Frank * Six 10-lb Parrotts Battery B, 1st New York Artillery: Cpt Rufus D. Pettit * Six 10-lb Parrotts Battery A, 2nd New York Artillery: Cpt William H. Hogan * Six 10-lb Parrotts
Second Division BG John Sedgwick	First Brigade BG Willis A. Gorman	2nd New York State Militia: Col George W.B. Tompkins 15th Massachusetts: Col Charles Devens 1st Minnesota: Col Alfred Sully
Second Division BG John Sedgwick	Second Brigade BG William Wallace Burns	69th Pennsylvania: Col Joshua T. Owen 71st Pennsylvania: Col Isaac J. Wistar 72nd Pennsylvania: Col DeWitt Clinton Baxter 106th Pennsylvania: Col Turner G. Morehead
Second Division BG John Sedgwick	Third Brigade BG Napoleon J.T. Dana	19th Massachusetts: Col Edward W. Hinks 20th Massachusetts: Col William R. Lee 7th Michigan: Col Ira R. Grosvenor 42nd New York: Col Edmund C. Charles
Second Division BG John Sedgwick	Artillery	Battery I, 1st U.S. Artillery: Lt Edmund Kirby * Six Napoleons Battery A, 1st Rhode Island Artillery: Cpt John A. Tompkins * Four 10-lb Parrotts, two 12-lb howitzers Battery B, 1st Rhode Island Artillery: Cpt Walter O. Bartlett * Four 10-lb Parrotts, two 12-lb howitzers Battery G, 1st Rhode Island Artillery: Cpt Charles Owen * Six 3-inch ordnance guns
Cavalry reserve	Unbrigaded	8th Illinois Cavalry: Col John F. Farnsworth 6th New York Cavalry : Maj Floyd Clarkson

N.B. The Third Division under BG Louis Blenker was detached in early April and transferred to the Mountain Department

III Corps

BG Samuel P. Heintzelman, Commanding
Cpt Chauncey McKeever, Chief of Staff

Division	Brigade	Regiments and others
First Division BG Fitz John Porter	First Brigade BG John H. Martindale	2nd Maine: Col Charles W. Roberts 18th Massachusetts: Col James Barnes 22nd Massachusetts: Col Jesse Gove 25th New York: Col Charles Johnson 13th New York: Col Elisha Marshall
First Division BG Fitz John Porter	Second Brigade BG George W. Morell	14th New York: Col James McQuade 4th Michigan: Col Dwight A. Woodbury 9th Massachusetts: Col Thomas Cass 62nd Pennsylvania: Ltc Jacob B. Sweitzer
First Division BG Fitz John Porter	Third Brigade BG Daniel Butterfield	17th New York: Col Henry S. Lansing 44th New York: Col Stephen W. Stryker 12th New York: Col Henry A. Weeks 83rd Pennsylvania: Col John W. McLane 16th Michigan: Col Thomas B. Stockton 1st Berdan Sharpshooters: Col Hiram Berdan
First Division BG Fitz John Porter	Artillery Cpt Charles Griffin	Battery D, 5th U.S. Artillery: Cpt Charles Griffin * Six 10-lb Parrotts Battery C, 1st Rhode Island Artillery: Cpt William B. Weeden Battery C, Massachusetts Artillery: Cpt Augustus C. Martin * Six Napoleons Battery E, Massachusetts Artillery: Cpt George D. Allen * Six 3-inch ordnance guns
Second Division BG Joseph Hooker	First Brigade BG Henry Morris Naglee	1st Massachusetts: Col Robert Cowdin 11th Massachusetts: Col William E. Blaisdell 26th Pennsylvania: Col William F. Small 2nd New Hampshire: Col Gilman Marston
Second Division BG Joseph Hooker	Second Brigade BG Daniel Sickles	70th New York: Col William Dwight 71st New York: Col George B. Hall 72nd New York: Col Nelson Taylor 73rd New York: Col William R. Brewster 74th New York: Col Charles K. Graham
Second Division BG Joseph Hooker	Third Brigade Col Samuel H. Starr	5th New Jersey: Col William Joyce Sewell 6th New Jersey: Col James T. Hatfield 7th New Jersey: Col Joseph W. Revere 8th New Jersey: Col Adolphus J. Johnson
Second Division BG Joseph Hooker	Artillery Cpt Norman J. Hall	Battery H, 1st U.S. Artillery: Cpt Norman J. Hall * Four 10-lb Parrotts, two 12-lb howitzers 4th New York Independent Battery: Cpt James E. Smith * Six 10-lb Parrotts 6th New York Independent Battery: Cpt William M. Bramhall * Six 3-inch ordnance guns Battery D, 1st New York Artillery: Cpt Thomas W. Osborn * Four 3-inch ordnance guns
Third Division BG Charles Smith Hamilton	First Brigade Col Charles D. Jameson	105th Pennsylvania: Col Amor A. McKnight 63rd Pennsylvania: Col Alexander Hays 57th Pennsylvania: Col Charles T. Campbell 87th New York: Col Stephen Hodge
Third Division BG Charles Smith Hamilton	Second Brigade BG David B. Birney	38th New York: Col J. H. Hobart Ward 40th New York: Col Edward J. Riley 3rd Maine: Col Moses B. Lakeman 4th Maine: Ltc Elijah Walker
Third Division BG Charles Smith Hamilton	Third Brigade BG Hiram G. Berry	2nd Michigan: Col Orlando M. Poe 3rd Michigan: Col Stephen G. Champlin 5th Michigan: Col Henry D. Terry 37th New York: Col John H. McCunn
Third Division BG Charles Smith Hamilton	Artillery Cpt James Thompson	Battery G, 2nd U.S. Artillery: Cpt James Thompson * Six Napoleons Battery B, New Jersey Artillery: Cpt John E. Beam * Four 10-lb Parrotts, two Napoleons Battery E, 1st Rhode Island Artillery: Cpt George E. Randolph * Four 10-lb Parrotts, two Napoleons
Cavalry reserve	Unbrigaded	3rd Pennsylvania Cavalry: Col William W. Averell

Porter's Division was combined with Sykes' Division of the Reserve Corps and McCall's Division of the First Corps to form the Fifth Corps (Provisional) on May 18, 1862.

IV Corps

BG Erasmus D. Keyes, Commanding
Ltc Charles C. Suydam

Division	Brigade	Regiments and others
First Division BG Darius N. Couch	First Brigade Col Henry Shaw Briggs	2nd Rhode Island: Col Horatio Rogers, Jr. 7th Massachusetts: Col David Allen Russell 10th Massachusetts: Col Henry Shaw Briggs 36th New York: Col Charles H. Innes
First Division BG Darius N. Couch	Second Brigade BG Lawrence P. Graham	67th New York: Col Julius W. Adams 65th New York: Col John Cochrane 23rd Pennsylvania: Col Thomas H. Neill 31st Pennsylvania: Col David H. Williams 61st Pennsylvania: Col Oliver H. Rippey
First Division BG Darius N. Couch	Third Brigade BG John J. Peck	98th Pennsylvania: Col John F. Ballier 102nd Pennsylvania: Col Thomas A. Rowley 93rd Pennsylvania: Col James M. McCarter 62nd New York: Col John L. Riker 55th New York: Col P. Regis de Trobriand
First Division BG Darius N. Couch	Artillery	Battery C, 1st Pennsylvania Artillery: Cpt Jeremiah McCarthy * Four 10-lb Parrotts Battery D, 1st Pennsylvania Artillery: Cpt Edward H. Flood * Four 10-lb Parrotts Battery E, 1st Pennsylvania Artillery: Cpt Theodore Miller * Four Napoleons Battery H, 1st Pennsylvania Artillery: Cpt James Brady * Four 10-lb Parrotts
Second Division BG W.F. "Baldy" Smith	First Brigade BG Winfield Scott Hancock	5th Wisconsin: Col Amasa Cobb 49th Pennsylvania: Col William H. Irwin 43rd New York: Col Francis L. Vinton 6th Maine: Col Hiram Burnham
Second Division BG W.F. "Baldy" Smith	Second Brigade BG William T.H. Brooks	2nd Vermont: Col Henry H. Whiting 3rd Vermont: Ltc Breed N. Hyde 4th Vermont: Col Edwin H. Stoughton 5th Vermont: Col Henry A. Smalley 6th Vermont: Ltc Nathan S. Lord
Second Division BG W.F. "Baldy" Smith	Third Brigade BG John Davidson	33rd New York: Col Robert F. Taylor 77th New York: Col James B. McKean 49th New York: Col Daniel D. Bidwell 7th Maine: Ltc Seldon Connor
Second Division BG W.F. "Baldy" Smith	Artillery Cpt Romeyn B. Ayres	Battery F, 5th U.S. Artillery: Cpt Romeyn B. Ayres * Four 10-lb Parrotts, two Napoleons 3rd New York Independent Battery: Cpt Thaddeus P. Mott * Four 10-lb Parrotts, two Napoleons Battery E, 1st New York Artillery: Cpt Charles C. Wheeler * Four 3-inch ordnance guns 1st New York Independent Battery: Cpt Terance J. Kennedy * Six 3-inch ordnance guns
Third Division BG Silas Casey	First Brigade Col William W.H. Davis	104th Pennsylvania: Ltc John W. Neilds 52nd Pennsylvania: Col John C. Dodge 56th New York: Col Charles Van Wyck 100th New York: Col James M. Brown 11th Maine: Col John C. Caldwell
Third Division BG Silas Casey	Second Brigade BG William High Keim	85th Pennsylvania: Col Joshua B. Howell 101st Pennsylvania: Col Joseph H. Williams 103rd Pennsylvania: Col Theodore F. Lehmann 96th New York: Col James Fairman
Third Division BG Silas Casey	Third Brigade BG Innis N. Palmer	85th New York: Col Jonathan S. Belknap 98th New York: Col William Dutton 92nd New York: Col Jonah Sanford 81st New York: Col Edwin Rose 93rd New York: Col John S. Crocker
Third Division BG Silas Casey	Artillery Col Guilford D. Bailey	7th New York Independent Battery: Cpt Peter C. Regan * Six 3-inch ordnance guns 8th New York Independent Battery: Cpt Butler Fitch * Six 3-inch ordnance guns Battery A, 1st New York Artillery: Cpt Thomas H. Bates * Six Napoleons Battery H, 1st New York Artillery: Cpt Joseph Spratt * Four 3-inch ordnance guns
Cavalry Reserve	Unbrigaded	6th New York Cavalry : ?

W.F. Smith's Division was combined with Franklin's Division of the First Corps to form the Sixth Corps (Provisional) on May 18, 1862.

Reserves

Division	Brigade	Regiments and others
Cavalry BG Philip St. George Cooke	First Brigade BG William H. Emory	5th U.S. Cavalry: Cpt Charles J. Whiting 6th U.S. Cavalry: Maj Lawrence A. Williams 6th Pennsylvania Cavalry: Col Richard H. Rush
Cavalry BG Philip St. George Cooke	Second Brigade Col George A.H. Blake	1st U.S. Cavalry: Ltc William N. Grier 8th Pennsylvania Cavalry: Col David McM. Gregg Barker's Squadron, Illinois Cavalry: Cpt Charles W. Barker
Artillery Col Henry J. Hunt	Horse Artillery Brigade Ltc William Hays	Battery A, 2nd U.S. Artillery: Cpt John C. Tidball * Six 3-inch ordnance rifles Batteries B & L, 2nd U.S. Artillery: Cpt James M. Robertson * Six 3-inch ordnance rifles Battery M, 2nd U.S. Artillery: Cpt Henry Benson * Six 3-inch ordnance rifles Batteries C & G, 3rd U.S. Artillery: Cpt Horatio G. Gibson * Six 3-inch ordnance rifles
Artillery Col Henry J. Hunt	Second Brigade Ltc George W. Getty	Battery K, 1st U.S. Artillery: Cpt William M. Graham * Six Napoleons Batteries E & G, 1st U.S. Artillery: Lt Alanson M. Randol * Six Napoleons Battery E, 2nd U.S. Artillery: Cpt J. Howard Carlisle * Six 20-lb Parrotts Batteries L & M, 3rd U.S. Artillery: Cpt John Edwards, Jr. * Six 10-lb Parrotts Batteries F & K, 3rd U.S. Artillery: Cpt La Rhett L. Livingston * Four 10-lb Parrotts Battery G, 4th U.S. Artillery: Lt Charles H. Morgan * Six Napoleons Battery K, 4th U.S. Artillery: Lt Francis W. Seeley * Six Napoleons Battery I, 5th U.S. Artillery: Cpt Stephen H. Weed * Six 3-inch ordnance guns Battery K, 5th U.S. Artillery: Cpt John R. Smead * Four Napoleons Battery A, 5th U.S. Artillery: Cpt Adelbert Ames * Four 10-lb Parrotts, two Napoleons
Artillery Col Henry J. Hunt	Third Brigade Maj Albert Arndt	Battery A, 1st New York Artillery Battalion: Cpt Otto Diedrich * Six 20-lb Parrotts Battery B, 1st New York Artillery Battalion: Cpt Adolph Voegele * Four 20-lb Parrotts Battery C, 1st New York Artillery Battalion: Cpt John Knieriem * Four 20-lb Parrotts Battery D, 1st New York Artillery Battalion: Cpt Edward Grimm * Six 32-lb howitzers
Engineers	Volunteers BG Daniel Phineas Woodbury	15th New York: Col J. McLeod Murphy 50th New York: Col Charles B. Stuart
Engineers	Regulars Cpt James Chatham Duane	Co. A, U.S. Engineers: Lt Chauncey B. Reese Co. B, U.S. Engineers: Lt Charles E. Cross Co. C, U.S. Engineers: Lt Orville E. Babcock
Engineers	Artillery Siege Train	1st Connecticut Heavy Artillery: Col Robert O. Tyler
Infantry	Regulars BG George Sykes	2nd U.S. Infantry : Ltc William Chapman 3rd U.S. Infantry : ? 4th U.S. Infantry : Ltc Robert C. Buchanan 6th U.S. Infantry : Cpt Levi C. Bootes 10th & 17th U.S. Infantry : ? 11th U.S. Infantry : Cpt DeLancey Floyd-Jones 12th U.S. Infantry : ? 14th U.S. Infantry : ? 5th New York (Duryee's Zouaves): Col Gouverneur K. Warren

Sykes' Division was combined with Porter's Division of the Third Corps and McCall's Division of the First Corps to form the Fifth Corps (Provisional) on May 18, 1862.

Other Troops from the Department of the Potomac

The following troops were part of the Department of the Potomac in March and April 1861, but were detached to maintain defense of the Potomac River line.

I Corps

On April 4, the First Corps was renamed the Department of the Rappahannock, with authority to include the District of Columbia, Maryland between the Potomac and Patuxent, and Virginia between the Blue Ridge and the Fredericksburg & Richmond Railroad.
MG Irvin McDowell, Commanding
Ltc Edmund Schriver, Chief of Staff
Unattached cavalry

1st New York Cavalry: Col Andrew T. McReynolds
2nd New York Cavalry: Col J. Mansfield Davies
4th New York Cavalry: Col Christian F. Dickel

Sharpshooters

2nd Regiment, Berdan Sharpshooters: Col Henry A.V. Post

Division	Brigade	Regiments and others
First Division BG William B. Franklin	First Brigade BG Philip Kearny until Apr 30 BG Georg W. Taylor	1st New Jersey: Lt Col Robert McAllister 2nd New Jersey: Col Isaac M. Tucker 3rd New Jersey: Col George W. Taylor 4th New Jersey: Col James H. Simpson
First Division BG William B. Franklin	Second Brigade BG Henry Slocum	16th New York: Col Joseph Howland 27th New York: Col Joseph J. Bartlett 5th Maine: Col Clark S. Edwards 96th Pennsylvania: Col Henry L. Cake
First Division BG William B. Franklin	Third Brigade BG John Newton	18th New York: Col William H. Young 31st New York: Col Calvin E. Pratt 32nd New York: Col Roderick N. Matheson 95th Pennsylvania: Col John M. Gosline
First Division BG William B. Franklin	Artillery Cpt Edward R. Platt	Battery D, 2nd U.S. Artillery: Cpt Edward R. Platt * Six Napoleons Battery A, Massachusetts Artillery: Cpt Josiah Porter * Four 10-lb Parrotts, two 12-lb howitzers Battery A, New Jersey Artillery: Cpt William Hexamer * Four 10-lb Parrotts, two 12-lb howitzers Battery F, 1st New York Artillery: Brady or Cpt William R. Wilson? * Four 3-inch ordnance guns
Second Division BG George A. McCall	First Brigade BG John F. Reynolds	1st Pennsylvania Reserves: Col R. Biddle Roberts 2nd Pennsylvania Reserves: Col William McCandless 5th Pennsylvania Reserves: Col Seneca G. Simmons 8th Pennsylvania Reserves: Col George S. Hays
Second Division BG George A. McCall	Second Brigade BG George Meade	3rd Pennsylvania Reserves: Col Horatio G. Sickel 4th Pennsylvania Reserves: Col Albert L. Magilton 7th Pennsylvania Reserves: Col Elisha B. Harvey 11th Pennsylvania Reserves: Col Thomas F. Gallagher
Second Division BG George A. McCall	Third Brigade BG Edward Ord	6th Pennsylvania Reserves: Col William Sinclair 9th Pennsylvania Reserves: Col Conrad F. Jackson 10th Pennsylvania Reserves: Col John S. McCalmont 12th Pennsylvania Reserves: Col John H. Taggart
Second Division BG George A. McCall	Skirmishers	1st Pennsylvania Reserve Rifles : Major Roy Stone
Second Division BG George A. McCall	Artillery Cpt Truman Seymour	Battery C, 5th U.S. Artillery: Cpt Truman Seymour * Six Napoleons Battery A, 1st Pennsylvania Artillery: Cpt Hezekiah Easton * Four Napoleons Battery B, 1st Pennsylvania Artillery: Cpt James H. Cooper * Six 10-lb Parrotts Battery G, 1st Pennsylvania Artillery: Cpt Mark Kern * Six 12-pounders
Third Division BG Rufus King	First Brigade BG Christopher C. Augur	84th New York : Col Edward Brush Fowler 22nd New York: Col Walter Phelps 24th New York: Col Timothy Sullivan 30th New York: Col Edward Frisby
Third Division BG Rufus King	Second Brigade BG Marsena R. Patrick	80th New York: Col George W. Pratt 21st New York: Col William F. Rogers 23rd New York: Col Henry C. Hoffman 35th New York: Col William C. Brown
Third Division BG Rufus King	Third Brigade BG John Gibbon	2nd Wisconsin: Col Edgar O'Connor 6th Wisconsin: Col Lysander Cutler 7th Wisconsin: Col William W. Robinson 19th Indiana: Col Solomon Meredith
Third Division BG Rufus King	Artillery	Battery B, 4th U.S. Artillery: Lt Joseph B. Campbell * Six Napoleons Battery D, 1st Rhode Island Artillery: Cpt John A. Monroe * Six 10-lb Parrotts Battery A, New Hampshire Artillery: Cpt George A. Gerrish * Six Napoleons Durell's Independent Battery, Pennsylvania Artillery: Cpt George W. Durrell? * Six 10-lb Parrotts

McCall's Division transferred to the Peninsula and was combined with Porter's Division of the Third Corps and Sykes' Division of the Reserve Corps to form the Fifth Corps (Provisional) on May 18, 1862. Franklin's Division transferred to the Peninsula and was combined with W.F. Smith's Division of the Fourth Corps to form the Sixth Corps (Provisional) on May 18, 1862.

V Corps

On April 4, the Fifth Corps was renamed the Department of Shenandoah with authority over Maryland between the Blue Ridge and Flintstone Creek, Virginia between the Blue Ridge and the modern-day border with West Virginia.
MG Nathaniel P. Banks, Commanding
Cpt Louis H. Pelouze, Acting Assistant Adjutant General
Unattached Infantry

28th Pennsylvania: Col John W. Geary
4th Regiment Potomac Home Brigade : ?

Division	Brigade	Regiments and others
First Division BG Alpheus S. Williams	First Brigade Col Dudley Donnelly	28th New York: Ltc Edwin F. Brown 5th Connecticut: Col George D. Chapman 46th Pennsylvania: Col Joseph F. Knipe 12th Indiana: ? 13th Massachusetts: Col Samuel H. Leonard
First Division BG Alpheus S. Williams	Second Brigade BG John Joseph Abercrombie	12th Massachusetts: Col Fletcher Webster 2nd Massachusetts: Col George H. Gordon 16th Indiana: ? 1st Potomac Home Brigade (Maryland): Col William P. Maulsby Zouaves d'Afrique : Cpt Charles H. T. Collis
First Division BG Alpheus S. Williams	Third Brigade Col George Henry Gordon	83rd New York: Col John W. Stiles 29th Pennsylvania: Col John K. Murphy 27th Indiana: Col Silas Colgrove 3rd Wisconsin: Col Thomas H. Ruger
First Division BG Alpheus S. Williams	Artillery Cpt Clermont L. Best	Battery F, 4th U.S. Artillery: Cpt Clermont L. Best * Six Napoleons 1st Maryland Battery : Cpt Robert B. Hampton * Four 10-lb Parrotts 2nd Maryland Battery : Cpt James Thompson * Four 10-lb Parrotts Battery F, 1st Pennsylvania Artillery: Cpt Ezra W. Matthews * Six 3-inch ordnance guns Battery M, 1st New York: Cpt George W. Cothran * Six 10-lb Parrotts Independent Battery E, Pennsylvania Artillery: Cpt Joseph E. Knapp * Six 10-lb Parrotts 15th Independent Battery, New York Artillery: Cpt Henry J. McMahon * Six 3-inch ordnance guns
Second Division BG James Shields	First Brigade Col Nathan Kimball	14th Indiana: Ltc William Harrow 4th Ohio 8th Ohio: Col Samuel S. Carroll 67th Ohio: Col Alvin C. Voris 7th Virginia: Col James Evans 84th Pennsylvania: Maj Walter Barrett
Second Division BG James Shields	Second Brigade Col Jeremiah C. Sullivan	5th Ohio: Col Samuel H. Dunning 62nd Ohio: Col Francis Bates Pond 66th Ohio: Col Charles Candy 13th Indiana: Ltc Robert S. Foster 39th Illinois: Col Thomas O. Osborn
Second Division BG James Shields	Third Brigade Col Erastus B. Tyler	7th Ohio: Ltc William R. Creighton 29th Ohio: Col Louis P. Buckley 7th Indiana: Col James Gavin 1st Virginia: Col Joseph Thoburn 110th Pennsylvania: Col William D. Lewis Andrew Sharpshooters: Cpt John Saunders
Second Division BG James Shields	Artillery Cpt Joseph C. Clark	Battery E, 4th U.S. Artillery: Cpt Joseph C. Clark * Six 10-lb Parrotts Battery A, 1st Virginia Artillery: Cpt John Jenks * Four 10-lb Parrotts, two Napoleons Battery B, 1st Virginia Artillery: Lt John V. Keeper * Two 10-lb Parrotts Battery H, 1st Ohio Artillery: Cpt James F. Huntington * Six 13-lb James Battery L, 1st Ohio Artillery: Cpt Frank C. Gibbs * Two 12-lb howitzers, four Napoleons Battery, 4th Ohio Artillery
Cavalry	Unbrigaded	1st Maine Cavalry: Col Samuel H. Allen 1st Vermont Cavalry: Col Lemuel Platt 1st Michigan Cavalry: Col Thornton F. Brodhead 1st Pennsylvania Cavalry: Col George D. Bayard 1st Rhode Island Cavalry: Col Alfred N. Duffié 5th New York Cavalry: Col Othniel De Forest 8th New York Cavalry: Col Samuel J. Crook Keys' Battalion, Pennsylvania Cavalry: Lt Hugh Keys Eighteen companies, Maryland Cavalry: Col Henry A. Cole One company, Virginia Cavalry: Col Henry Anisansel

Shields' Division was transferred to the Department of the Rappahannock on May 10, 1862

District of Washington

BG James S. Wadsworth, Commanding

Regiments and others	Camp Location
1st New Jersey Cavalry: Col William Halstead	Alexandria City
4th Pennsylvania Cavalry: Col James H. Childs	East of the Capitol
10th New Jersey: Col William Bryan	Bladensburg Road
104th New York: Col John Rohrbach	Kalorama Heights
1st Wisconsin Heavy Artillery: ?	Fort Cass
New York Artillery : ?	Fort Ethan Allen Fort Marcy
Depot of New York Light Artillery: ?	Camp Barry
2nd District of Columbia: Col Charles M. Alexander	Washington City
26th Pennsylvania: Col William F. Small	G Street Wharf
26th New York: Col William H. Christian	Fort Lyon
95th New York: Col George H. Biddle	Camp Thomas
94th New York: Col Henry K. Viele Detachment of 88th Pennsylvania: Maj George W. Gile	Alexandria City
91st Pennsylvania: Col Edgar I. Gregory	Franklin Square Barracks
4th New York Heavy Artillery: Col T.D. Doubleday	Fort Carroll Fort Greble
112th Pennsylvania: Col Charles Angeroth	Fort Saratoga
76th New York: Ltc John D. Shaul	Fort Massachusetts
59th New York: Col William L. Tidball	Fort Pennsylvania
Detachment of 88th Pennsylvania: ?	Fort Good Hope
99th Pennsylvania: Col Peter Fritz	Fort Mahon
2nd New York Light Artillery: ?	Fort Ward Fort Worth Fort Blenker
107th Pennsylvania: Col Thomas A. Zeigel 54th Pennsylvania: Col Jacob M. Campbell	Kendall Green
Dickenson's Light Artillery 86th New York: Col Benajah P. Baily Detachment of 88th Pennsylvania: Col George P. McLean	East of the Capitol
1st Massachusetts Heavy Artillery: Col Thomas R. Tannatt 56th Pennsylvania: Col Sullivan A. Meredith	Fort Albany Fort Tillinghast Fort Richardson Fort Runyon Fort Jackson Fort Barnard Fort Craig Fort Scott
Detachment of 4th U.S. Artillery: ? 37th New York: Col John H. McCunn	Fort Washington
97th New York: Col Charles W. Wheelock 101st New York: Col Enrico Fardella~~91st New York: Col Jacob Van Sandt~~ 12th Virginia: Col John B. Klunk	Fort Corcoran

Railroad Guards
Col Dixon S. Miles

6th New York Cavalry : Col Thomas Devin~~10th New York Cavalry : Col John Lemmon~~
11th New York Cavalry : Col James B. Swain
2nd Pennsylvania Cavalry : Col Richard Butler Price

Troops Around Baltimore

On March 22, the Middle Department was created with authority over Pennsylvania, New Jersey, Delaware, and the Eastern Shore of Maryland and Virginia, as well as the Maryland counties of Cecil, Hartford, Baltimore, and Anne Arundel. Dix remained in command.
MG John A. Dix, Commanding
Maj Daniel Tompkins Van Buren, Chief of Staff and Acting Assistant Adjutant General

Type of Units	Regiments and others
Cavalry	1st Maryland Cavalry: Cpt Henry A. Cole? Purnell Legion Cavalry: Cpt Robert E. Duvall
Artillery	Battery I, 2nd U.S. Artillery: Cpt Albert J.S. Molinard Battery A, Maryland Light Artillery: Cpt John W. Wolcott Battery L, 1st New York Artillery: Cpt John A. Reynolds Independent Battery ?, Pennsylvania Artillery: ? Independent Battery ?, Pennsylvania Artillery: ?
Infantry	3rd New York: Col Samuel M. Alford 4th New York: Col Alfred W. Taylor 11th Pennsylvania: Col Richard Coulter 87th Pennsylvania: Col George Hay 111th Pennsylvania: Col Matthew Schlaudecker Detachment, 21st Massachusetts: ? 2nd Delaware: Col W. Henry Wharton 2nd Maryland: Col John Sommer 1st Eastern Shore Home Guard : Col James Wallace 2nd Eastern Shore Home Guard : Col Robert S. Rogers Purnell Legion Infantry: Col Samuel L. Graham

Department of Virginia

The Department of Virginia constituted an area 60 miles from Fort Monroe. McClellan had received permission to absorb it into his army as a division of the First Corps, but it was rescinded shortly after he arrived on the Peninsula.
MG John E. Wool, Commanding

Location	Regiments and others
Fort Monroe Maj Joseph Roberts	10th New York: Col John E. Bendix 99th New York : Maj Richard Nixon 7th Independent Battery, Massachusetts Artillery: Cpt Phineas Alonzo Davis Detachment, 4th U.S. Artillery: ? 2nd Independent Battery, Wisconsin Artillery: Cpt Ernst F. Herzberg 4th Independent Battery, Wisconsin Artillery: Cpt John F. Vallee
Camp Hamilton Col Max Weber	1st Delaware: Col John W. Andrews 16th Massachusetts: Col Powell T. Wyman 1st Michigan: Col John C. Robinson 20th New York: Ltc Francis Weiss 99th New York : Col David W. Wardop 58th Pennsylvania: Col John R. Jones Battery D, 4th U.S. Artillery: Cpt Frederick M. Follett 11th Pennsylvania Cavalry: Col Joseph Harlan 1st New York Mounted Rifles : Maj Charles C. Dodge
Camp Butler BG Joseph K. F. Mansfield	20th Indiana: Col William L. Brown 5th Maryland: Col William L. Schley 29th Massachusetts: Col Ebenezer W. Peirce 1st New York: Col Garrett Dyckman 2nd New York: Col Joseph B. Carr 7th New York: Col Edward Kapff 11th New York: Col Charles McK. Loeser Battery L, 4th U.S. Artillery: Cpt Robert V.W. Howard
Fort Wool Ltc Gustave B. Helleday	99th New York : Ltc Gustave B. Helleday