< to June • July 1864 • to August >
Commanded by:
Major General Lew Wallace (to 7/11)
Major General Edward O.C. Ord (to 7/29)
Major General Lew Wallace
On July 9 Major General Lew Wallace gathered what few rear area troops he could scrape together and met Confederate Major General Jubal Early’s Army of the Valley on the Monocacy River just outside Frederick, Maryland. A handful of reinforcements who had been rushed north from the veteran Sixth Corps of the Army of the Potomac helped keep the fight from becoming a disaster, but Union forces were in retreat by late afternoon. Grant, who had a low opinion of Wallace that dated back to the Battle of Shiloh, replaced him with Major General Edward O.C. Ord. But it became clear that Wallace’s sacrificial fight had delayed Early for a critical day that allowed Union reinforcements to each Washington and almost certainly saved the capital from capture. Grand had Wallace reinstated.
| First Separate Brigade | Brigadier General Erastus B. Tyler |
|
| 1st Delaware Cavalry Regiment | from Army Potomac | |
| 1st Maryland Eastern Shore Regiment | Colonel James Wallace | |
| 3rd Maryland Potomac Home Brigade | Colonel Stephen W. Downey | to Army Shenandoah, 6 Corps, Kenly’s Brig. |
| 12th Maryland Infantry Regiment | new, from Baltimore | |
| 1st New Jersey National Guard | from New Jersey | |
| 93rd New York National Guard | William R. W. Chambers | from New York |
| 144th Ohio Infantry Regiment | Colonel Samuel H. Hunt | to Army Shenandoah, 6 Corps, Kenly’s Brig. |
| 157th Ohio Infantry Regiment | Colonel George W. McCook | |
| 195th Pennsylvania Infantry Regiment | Colonel William B. Thomas | from Pennsylvania |
| 3rd Pennsylvania Heavy Artillery, Co. H | Captain William D. Rank | from 3 Sep. Brig. (below) |
| Second Separate Brigade | Brevet Brigadier General William W. Morris | |
| 131st Ohio Infantry Regiment | Colonel John G. Lowe | |
| 137th Ohio Infantry Regiment | Colonel L. A. Harris | |
| 192nd Pennsylvania Infantry Regiment | Colonel William B. Thomas | from Pennsylvania |
| Third Separate Brigade | Brigadier General John R. Kenly (to 7/20) Brigadier General Henry H. Lockwood |
|
| 7th Delaware Infantry Regiment | from Delaware | |
| 11th Maryland Infantry Regiment | new, from Baltimore | |
| 5th Massachusetts Infantry Regiment | from Massachusetts | |
| 8th Massachusetts Infantry Regiment | from Massachusetts | |
| 144th Ohio Infantry Regiment, Co. G | ||
| 149th Ohio Infantry Regiment | Colonel Allison L. Brown | |
| 159th Ohio Infantry Regiment | Colonel Lyman J. Jackson | |
| 193rd Pennsylvania Infantry Regiment | Colonel John B. Clark | from Pennsylvania 7/19 |
| 194th Pennsylvania Infantry Regiment | Colonel James Nagle | from Pennsylvania 7/24 |
| 196th Pennsylvania Infantry Regiment | Colonel Harmanus Neff | from Pennsylvania 7/9 |
| 197th Pennsylvania Infantry Regiment | Colonel John R. Haslett | from Pennsylvania 7/22 |
| Smith’s Maryland Cavalry Company | Captain G.W.P. Smith | |
| Baltimore (MD) Battery | to Dept. WV, Dist. Harpers Ferry | |
| 3rd Pennsylvania Heavy Artillery, Co. H | Captain William D. Rank | to 1 Sep. Brig. (above) |
| Fort Delaware | ||
| Ahl’s Delaware Heavy Artillery Co. | ||
| Pennsylvania Independent Battery A | ||
| Pennsylvania Independent Battery G | Captain Stan. Miotkowski |