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Commanded by Major General Samuel P. Heintzelman
Defences North of the Potomac Lieutenant Colonel Joseph A. Haskin
First Brigade Colonel August A. Gibson
2nd Pennsylvania Heavy Artillery Colonel August A. Gibson
1st Vermont Heavy Artillery Colonel James M. Warner
Second Brigade Colonel Lewis O. Morris
1st Maine Heavy Artillery
7th New York Heavy Artillery Colonel Lewis O. Morris
9th New York Heavy Artillery
9th New York Independent Battery
Third Brigade Colonel A. Piper
10th New York Heavy Artillery
Defences South of the Potomac Brigadier General Gustavus A. DeRussy
First Brigade Colonel T. R. Tannatt (to 8/11)
Colonel J.N.G. Whistler
1st Massachusetts Heavy Artillery
2nd New York Heavy Artillery
5th New York Heavy Artillery,
Companies
I,K,L&M
Second Brigade Colonel L. W. Wessells
19th Connecticut Infantry Regiment
3rd New York Heavy Artillery Battalion Lieutenant Colonel Adam Senges
Third Brigade Colonel H. L. Abbot
1st Connecticut Heavy Artillery
1st Rhode Island Artillery, Battery H
1st Wisconsin Heavy Artillery, Bat. A
Fourth Brigade Colonel H. H. Hall (to 8/6)
Lieutenant Colonel T. Allcock
2nd Massachusetts Cavalry Regiment from King’s Div. (below)
4th New York Heavy Artillery Colonel H. H. Hall from 1st Brig. (above)
King’s Division Brigadier General Rufus King
1st Brigade (“Corcoran Legion”) Brigadier General Michael Corcoran
155th New York Infantry Regiment Colonel William McEvily
164th New York Infantry Regiment Colonel James McMahon
170th New York Infantry Regiment Colonel James D. McIvor
182nd New York Infantry Regiment Colonel Mathew Murphy
Not Brigaded
4th Delaware Infantry Regiment Colonel A.H. Grimshaw
17th New York Independent Battery
2nd Massachusetts Cavalry Regiment to DeRussey’s Div., 4 Brig. (above)
157th Pennsylvania Infantry (4 cos.)
District of Washington Brigadier General J. H. Martindale
2nd District of Columbia Infantry Regiment Colonel Charles M. Alexander
34th Massachusetts Infantry Regiment Colonel George D. Wells to W. Va., Maryland Heights Div
11th New York Cavalry, Cos. E, F & I
14th New Hampshire Infantry Regiment Colonel Robert Wilson
153rd New York Infantry Regiment Colonel Edwin P. Davis
178th New York Infantry Regiment Lieutenant Colonel Charles F. Smith from Defenses S. Potomac, 3 Brig.
150th Pennsylvania Infantry, Co. K Captain David Derickson Lincoln’s Bodyguard
157th Pennsylvania Infantry (4 cos.)
District of Alexandria Brigadier General John P. Slough
Slough’s Independent Brigade Brigadier General John P. Slough
1st District of Columbia Infantry Regiment
Pennsylvania Independent Battery H
Second Brigade, Pennsylvania Reserves Colonel Horatio G. Sickel
3rd Pennsylvania Reserves Regiment Lieutenant Colonel John Clark
4th Pennsylvania Reserves Regiment Colonel Richard H. Woolworth
7th Pennsylvania Reserves Regiment Colonel Henry C. Bolinger
8th Pennsylvania Reserves Regiment Colonel Silas M. Baily
Independent Cavalry Brigade Colonel C. R. Lowell, Jr.
2nd Massachusetts Cavalry Regiment
13th New York Cavalry (Companies A-F) Lieutenant Colonel Henry S. Gansevoort from New York
16th New York Cavalry (Companies A-D)
Light Artillery Camp (Camp Barry)
2nd Connecticut Light Battery to Dept. East New York City
1st Delaware Battery to Dept. East New York City
7th Massachusetts Battery
10th Michigan Battery
1st New York Artillery, Battery F
1st New York Artillery, Battery H
10th New York Independent Battery Lieutenant Charles T. Bruen
19th New York Independent Battery .
12th Ohio Independent Battery
1st Pennsylvania Artillery, Battery H
Pennsylvania Independent Battery D to Dept. WV, MD Heights Div.
1st West Virginia Artillery, Battery F
5th United States Artillery, Battery I from Army Potomac 5 Corps Art.
5th United States Artillery, Battery L from 1 Brig. 2 Div. 8  Corps