June 1861 • to July >
Commanded by Brigadier General Samuel P. Heintzelman
| Unattached | ||
| 4th United States Cavalry, Cos. A&E | Captain James B. McIntyre | from Ft. Leavenworth, Kansas |
| First Brigade | Colonel W. B. Franklin | |
| 11th Massachusetts Infantry Regiment | Colonel G. Clark | from Massachusetts 6/26 |
| 4th Pennsylvania Infantry Regiment | Colonel John Hartranft | from Dept. Washington 6/3 |
| 5th Pennsylvania Infantry Regiment | Colonel R. P. McDowell | from Dept. Washington 6/3 |
| 1st United States Artillery, Battery I | Captain J. B. Ricketts | from Regular Army |
| Second Brigade | Col. O. B. Wilcox | |
| 38th New York Infantry Regiment | Colonel J. H. Ward | from New York 6/19 |
| 1st Michigan Infantry Regiment | Major A. F. Bidwell | from Dist. Washington |
| 4th Michigan Infantry Regiment | Colonel D. A. Woodbury | from Michigan 6/26 |
| 2nd United States Artillery, Battery D | Captain R. Arnold | from Regular Army |
| Third Brigade | Col. O. O. Howard | |
| 3rd Maine Infantry Regiment | Major H. G. Staples | from Maine 6/4 |
| 4th Maine Infantry Regiment | Colonel H. G. Berry | from Maine 6/20 |
| 5th Maine Infantry Regiment | Colonel M. H. Dunnell | from Maine 6/26 |
| 2nd Vermont Infantry Regiment | Colonel H. Whiting | from Vermont 6/24 |