< to August • September 1862 • to October >
Commanded by Major General John Wool
| Defences of Baltimore | Colonel W. H. Morris | |
| 17th Indiana Battery | ||
| 18th Connecticut Infantry Regiment | Colonel William G. Ely | |
| 1st Maryland Infantry Regiment | Colonel Nathan T. DuShane | to Williamsport (below) |
| Purnell Legion Cavalry (Maryland) Cos. B & C | ||
| Baltimore Maryland Battery | to Williamsport (below) | |
| 38th Massachusetts Infantry Regiment | Colonel Timothy Ingragham | from Massachusetts 8/30 |
| 14th New Jersey Infantry Regiment | Colonel William S. Truex | from New Jersey 9/2 |
| 5th New York Heavy Artillery | Colonel Samuel Graham | |
| 7th New York State Militia | Colonel Marshall Lefferts | mustered out 9/5 |
| 19th New York State Militia | Lt. Colonel Lloyd Aspinwall | mustered out 9/6 |
| 22nd New York State Militia | Colonel James Monroe | mustered out 9/5 |
| 37th New York State Militia | Colonel Charles Roome | mustered out 9/2 |
| 47th New York State Militia | Colonel Jeremiah V. Meserole | mustered out 9/1 |
| 109th New York Infantry Regiment | Colonel George Hay | |
| 110th New York Infantry Regiment | Lt. Colonel James Galligher | |
| 114th New York Infantry Regiment | Colonel Elisha B. Smith | from Norwich, NY 9/6 |
| 116th New York Infantry Regiment | Colonel Edward P. Chapin | from Buffalo, NY, 9/5 |
| 128th New York Infantry Regiment | Colonel David S. Cowles | from Hudson, NY 9/5 |
| 135th New York Infantry Regiment | Colonel Lewis G. Morris (to 9/2) Colonel William H. Morris |
from New York 9/5 |
| 13th Pennsylvania Cavalry Regiment | Lt. Colonel James Galligher | |
| 138th Pennsylvania Infantry Regiment | Colonel Charles L.K. Sumwalt | |
| 2nd United States Artillery, Battery I | at Fort McHenry | |
| Annapolis | ||
| 3rd Maryland Potomac Home Brig. | Colonel Stephen W. Downey | from paroled prisoners |
| Purnell Legion Cavalry (Maryland) Co. B | ||
| 131st New York Infantry Regiment | Colonel Charles S. Turnbull | from New York 9/14 |
| 67th Pennsylvania Infantry Regiment | Colonel John F. Staunton | |
| District of the Eastern Shore | Henry H. Lockwood | |
| 1st Maryland Eastern Shore Regiment | Colonel David P. DeWitt | |
| 2nd Maryland Eastern Shore Regiment | Colonel Edward Wilkins | |
| Purnell Legion Cavalry (Maryland) Co. A | ||
| Railroad District | Brigadier General Benjamin F. Kelly | |
| 1st Illinois Artillery, Battery L | to Dept. Ohio, RR Dist. W. Virginia | |
| 23rd Illinois Infantry Regiment | to Dept. Ohio, RR Dist. W. Virginia | |
| 65th Illinois Infantry Regiment | Captured at Harpers Ferry | |
| 1st Maryland Potomac Home Brig. | Colonel William P. Maulsby | Captured at Harpers Ferry |
| 2nd Maryland Potomac Home Bde. | Colonel Robert Bruce | to Dept. Ohio, RR Dist. W. Virginia |
| 106th New York Infantry Regiment | Colonel Schuyler F. Judd | |
| 84th Ohio Infantry Regiment | Colonel William Lawrence | to Dept. Ohio, RR Dist. W. Virginia |
| 54th Pennsylvania Infantry Regiment | Colonel Jacob M. Campbell | to Dept. Ohio, RR Dist. W. Virginia |
| 87th Pennsylvania Infantry Regiment | Colonel George Hay | to Dept. Ohio, RR Dist. W. Virginia |
| Ringgold Pennsylvania Cavalry | to Dept. Ohio, RR Dist. W. Virginia | |
| Washington Co. Pennsylvania Cavalry | to Dept. Ohio, RR Dist. W. Virginia | |
| Loudon Virginia Rangers | to Dept. Ohio, RR Dist. W. Virginia | |
| 6th West Virginia Infantry Regiment | Colonel Nathan Wilkinson | to Dept. Ohio, RR Dist. W. Virginia |
| 10th West Virginia Infantry Regiment | Colonel Thomas M. Harris | to Dept. Ohio, RR Dist. W. Virginia |
| 11th West Virginia Infantry Regiment | Colonel John C. Rathbone | to Dept. Ohio, RR Dist. W. Virginia |
| 12th West Virginia Infantry Regiment | Colonel John B. Klunk | to Dept. Ohio, RR Dist. W. Virginia |
| West Virginia Artillery, Battery F | to Dept. Ohio, RR Dist. W. Virginia | |
| West Virginia Artillery, Battery G | to Dept. Ohio, RR Dist. W. Virginia | |
| Railroad Brigade | Colonel Dixon S. Miles (mw 9/16) | |
| 2nd Illinois Artillery, Battery M | Captured at Harpers Ferry | |
| 26th Indiana Battery | Captured at Harpers Ferry | |
| 1st Maryland Potomac Home Brig. | Colonel William P. Maulsby | Captured at Harpers Ferry |
| 1st Maryland Potomac Home Brig. Cavalry | Captain Henry A. Cole | to 12 Corps |
| 3rd Maryland Potomac Home Brig. | Captured at Harpers Ferry | |
| Patapsco Maryland Guard | Colonel James W. McMillan | to defences Baltimore |
| 5th New York Heavy Artillery, Cos. A&F | Captured at Harpers Ferry | |
| 8th New York Cavalry Regiment | Colonel Benjamin F. Davis | to Army Potomac Cavalry |
| 12th New York State Militia | Captured at Harpers Ferry | |
| 39th New York Infantry Regiment | Colonel Frederick D’Utassy | from Army of Virginia, White’s Brig. Captured at Harpers Ferry |
| 115th New York Infantry Regiment | Colonel Simeon Sammon | from New York Captured at Harpers Ferry |
| 125th New York Infantry Regiment | Colonel George Willard | from New York Captured at Harpers Ferry |
| 126th New York Infantry Regiment | Colonel Eliakim Sherrill | from New York Captured at Harpers Ferry |
| 32nd Ohio Infantry Regiment | Colonel Thomas H. Ford | from Army Virginia, 1 Corps 1 Div. 2 Brig. Captured at Harpers Ferry |
| 60th Ohio Infantry Regiment | Clonel William H. Trimble | Captured at Harpers Ferry |
| 87th Ohio Infantry Regiment | Colonel Henry B. Banning | Captured at Harpers Ferry |
| 9th Vermont Infantry Regiment | Colonel George Stannard | from Army of Virginia, Piatt’s Brig. Captured at Harpers Ferry |
| Williamsport, Maryland Brigade | Brigadier General John R. Kenly | |
| 1st Maryland Infantry Regiment | Colonel Nathan T. DuShane | |
| 4th Maryland Infantry Regiment | Colonel William J.L. Nicodemus | Organized at Baltimore |
| 6th Maryland Infantry Regiment | Colonel George R. Howard | Organized at Baltimore |
| 7th Maryland Infantry Regiment | Colonel Edwin H. Webster | Organized at Baltimore |
| 8th Maryland Infantry Regiment | Colonel Andrew W. Denison | Organized at Baltimore |
| Baltimore Maryland Battery | ||