| Defenses North of the Potomac | 
Lieutenant Colonel Joseph A. Haskin | 
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| First Brigade | 
Colonel Augustus A. Gibson | 
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| 3rd Maine Battery | 
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| 2nd Pennsylvania Heavy Artillery | 
Colonel Augustus A. Gibson | 
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| 143rd Pennsylvania Infantry Regiment | 
Colonel Edmund L. Dana | 
from Pennsylvania | 
| 11th Vermont Infantry Regiment | 
Colonel James M. Warner | 
serving as heavy artillery | 
| Second Brigade | 
Colonel Lewis O. Morris | 
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| 16th Indiana Battery | 
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| 18th Maine Infantry Regiment | 
Colonel Daniel Chaplin | 
serving as heavy artillery | 
| 22nd New York Independent Battery | 
Captain John D. Numan | 
from New York | 
| 113th New York Infantry Regiment | 
Colonel Lewis O. Morris | 
serving as heavy artillery | 
| 138th New York Infantry Regiment | 
Colonel Joseph Welling | 
serving as heavy artillery | 
| 117th New York Infantry, 2nd Battalion | 
Colonel William R. Pease | 
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| Third Brigade | 
Colonel William R. Pease | 
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| 5th Battalion New York Heavy Artillery | 
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consolidated into 10th NY HV Art. (below) | 
| 6th Battalion New York Heavy Artillery | 
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consolidated into 10th NY HV Art. (below) | 
| 7th Battalion New York Heavy Artillery | 
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consolidated into 10th NY HV Art. (below) | 
| 10th New York Heavy Artillery Regiment | 
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created from 4, 5 & 7 NY Hv. Art. Bns. | 
| 117th New York Infantry, 1st Battalion | 
Colonel William R. Pease | 
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| District of Alexandria | 
Brigadier General John P. Slough | 
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| 1st District of Columbia Infantry Regt. | 
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| 153rd New York Infantry Regiment | 
Colonel Duncan McMartin | 
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| 11th Rhode Island Infantry Regiment | 
Colonel Edwin Metcalf (to 11/11) 
Lieutenant Colonel Horatio Rogers | 
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| District of Alexandria Artillery | 
Brigadier General John Tyler | 
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| 1st Connecticut Heavy Artillery | 
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| 19th Connecticut Infantry Regiment | 
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| 1st Massachusetts Heavy Artillery | 
Lieutenant Colonel Levi P. Wright | 
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| 34th Massachusetts Infantry Regiment | 
Colonel George D. Wells | 
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| 2nd New York Heavy Artillery Regiment | 
Colonel Gustave Wagner | 
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| 1st Wisconsin Heavy Artillery | 
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| Abercrombies’ Division | 
Brigadier General John J. Abercrombie | 
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| Provisional (First) Brigade | 
Colonel Clarence Buell | 
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| 152nd New York Infantry Regiment | 
Colonel Leonard Boyer | 
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| 153rd New York Infantry Regiment | 
Colonel Duncan McMartin | 
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| 169th New York Infantry Regiment | 
Lieutenant Colonel John McConihe | 
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| Second Brigade | 
Brigadier General R. Cowden | 
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| 22nd Connecticut Infantry Regiment | 
Colonel George S. Burnham | 
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| 40th Massachusetts Infantry Regiment | 
Colonel Burr B. Porter | 
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| 141st New York Infantry Regiment | 
Colonel Samuel G. Hatheway | 
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| 16th West Virginia Infantry Regiment | 
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| Third Brigade | 
Colonel William Gurney | 
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| 127th New York Infantry Regiment | 
Lieutenant Colonel Stewart Woodford | 
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| 142nd New York Infantry Regiment | 
Colonel Roscius W. Judson | 
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| 143rd New York Infantry Regiment | 
Colonel David P. De Witt | 
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| 144th New York Infantry Regiment | 
Colonel Robert S. Hughston | 
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| Artillery | 
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| 9th Massachusetts Battery | 
Captain John Bigelow | 
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| 17th New York Independent Battery | 
Captain George T. Anthony | 
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| 4th New York Heavy Artillery Regiment | 
Colonel Gustavus A. DeRussy | 
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| Casey’s Division | 
Major General Silas Casey | 
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| First Brigade | 
Colonel Dexter Wright | 
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| 15th Connecticut Infantry Regiment | 
Colonel Dexter R. Wright | 
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| 13th New Hampshire Infantry Regiment | 
Colonel Aaron F. Stevens | 
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| 12th Rhode Island Infantry Regiment | 
Colonel George H. Browne | 
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| 25th New Jersey Infantry Regiment | 
Colonel Andrew Derrom | 
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| 27th New Jersey Infantry Regiment | 
Colonel George W. Mindil | 
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| Second Brigade | 
Colonel Asa P. Blunt (to 11/5) 
Brigadier General E. H. Stoughton 
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| 12th Vermont Infantry Regiment | 
Colonel Asa P. Blunt | 
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| 13th Vermont Infantry Regiment | 
Colonel Francis V. Randall | 
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| 14th Vermont Infantry Regiment | 
Colonel William T. Nicholls | 
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| 15th Vermont Infantry Regiment | 
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| 16th Vermont Infantry Regiment | 
Colonel Wheelock G. Veazey | 
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| 2nd Connecticut Independent Battery | 
Captain John William Sterling | 
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| Third Brigade | 
Colonel Francis Fessenden | 
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| 22nd Maine Infantry Regiment | 
Colonel Simon G. Jerrard | 
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| 25th Maine Infantry Regiment | 
Colonel Francis Fessenden | 
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| 26th Maine Infantry Regiment | 
Colonel Nathan H. Hubbard | 
moved to Fort Monroe, then Louisiana | 
| 27th Maine Infantry Regiment | 
Colonel Rufus Tapley | 
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| 151st Pennsylvania Infantry Regiment | 
Colonel Harrison Allen | 
from Pennsylvania | 
| Keystone (PA) Battery | 
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| 11th Massachusetts Independent Battery | 
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| Provisional Brigade | 
Major General Silas Casey | 
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| 22nd New Jersey Infantry Regiment | 
Colonel Abraham G. Demarest | 
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| 24th New Jersey Infantry Regiment | 
Colonel Colonel William B. Robertson | 
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| 28th New Jersey Infantry Regiment | 
Colonel Moses Nelson Wisewell | 
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| 29th New Jersey Infantry Regiment | 
Colonel Edwin F. Applegate | 
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| 30th New Jersey Infantry Regiment | 
Colonel Alexander F. Donaldson | 
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| 31st New Jersey Infantry Regiment | 
Colonel Alexander P. Berthoud | 
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| Grover’s Brigade | 
Brigadier General Cuvier Grover 
Colonel A. B. Jewett 
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| 22nd Maine Infantry Regiment | 
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| 23rd Maine Infantry Regiment | 
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| 39th Massachusetts Infantry Regiment | 
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| 14th New Hampshire Infantry Regiment | 
Colonel Rober Wilson | 
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| 10th Vermont Infantry Regiment | 
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| 10th Massachusetts Battery | 
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| Whipple’s Division | 
Brigadier General Amiel W. Whipple | 
to Army Potomac 3 Corps 3 Div. | 
| Piatt’s Brigade | 
Brigadier General Abram S. Piatt | 
to Army Potomac 3 Corps 3 Div. 1 Brig. | 
| 86th New York Infantry Regiment | 
Colonel Benajah P. Bailey | 
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| 124th New York Infantry Regiment | 
Colonel A. Van Horne Ellis | 
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| 122nd Pennsylvania Infantry Regiment | 
Colonel Emlen Franklin | 
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| Second Brigade | 
Colonel S. S. Carroll | 
to Army Potomac 3 Corps 3 Div. 2 Brig. | 
| 163rd New York Infantry Regiment | 
Colonel F. H. Braulich | 
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| 84th Pennsylvania Infantry Regiment | 
Colonel Samuel M. Bowman | 
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| 110th Pennsylvania Infantry Regiment | 
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| Unassigned units | 
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| 12th New Hampshire Infantry Regiment | 
Colonel Joseph H. Potter | 
to Army Potomac 3 Corps 3 Div. 2 Brigade | 
| 11th New York Independent Battery | 
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to Army Potomac 3 Corps 3 Div. Artillery | 
| 127th Pennsylvania Infantry Regiment | 
Colonel William W. Jennings | 
to Army Potomac 2 Corps 2 Div. 3 Brig. | 
| Wrigley’s (PA) Engineer Company | 
Captain H.E. Wrigley | 
to Harpers Ferry | 
| Cavalry Brigade | 
Colonel R. Butler Price | 
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| 1st Michigan Cavalry Regiment | 
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| 5th New York Cavalry Regiment | 
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| 1st Ohio Cavalry, Cos. A & C | 
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| 2nd Pennsylvania Cavalry Regiment  | 
Colonel Richard B. Price | 
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| 1st Vermont Cavary Regiment | 
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| 1st West Virginia Cavalry (8 Cos.) | 
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| Railroad Guard | 
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| 11th New York Cavalry Regiment | 
Colonel James B. Swain | 
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| Camp Barry, Light Artillery Camp | 
General William F. Barry | 
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| 1st Delaware Battery | 
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| 10th Michigan Battery  | 
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from Michigan | 
| 12th New York Independent Battery | 
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| 16th New York Independent Battery | 
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| 19th New York Independent Battery | 
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| West Virginia Artillery, Battery A | 
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| Unassigned Infantry | 
| 2nd District of Columbia Infantry Regt. | 
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| 10th New Jersey Infantry Regiment | 
Colonel William R. Murphy | 
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| 147th New York Infantry Regiment | 
Colonel Andrew S. Warner | 
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| 135th Pennsylvania Infantry Regiment | 
Colonel James R. Porter | 
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| 149th Pennsylvania Infantry Regiment | 
Colonel Roy Stone | 
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| 150th Pennsylvania Infantry Regiment | 
Colonel Langhorne Wister | 
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