August 1861 • to September >

Commanded by Major General John Dix

On August 24 the Department of Pennsylvania merged with the Department of the Potomac. Dix’s Division, headquartered in Baltimore, had been the troops of the Department of Annapolis, who were redesignated Department of Maryland on July 19, merged into the Department of Pennsylvania on July 25 and then into the Army of the Potomac.

1st Delaware Militia  Colonel Henry H. Lockwood mustered out 8/30
20th Indiana Infantry Regiment Colonel William L. Brown
21st Indiana Infantry Regiment Colonel James W. McMillan
17th Massachusetts Infantry Regiment Colonel Thomas I.C. Amory from Lynnfield, Ma. 8/23
7th Maine Infantry Regiment Colonel Thomas H. Marshall From Augusta, Me., 8/23
3rd New York Infantry Regiment Lt. Colonel Samuel M. Alford promoted colonel 8/26
4th New York Infantry Regiment Colonel Alfred W. Taylor
5th New York Infantry Regiment Colonel C. Schwartzwaelder
1st Pennsylvania Reserves Colonel R. Biddle Roberts to 1 Brig., McCall’s Div. 8/30
19th Pennsylvania Infantry Regiment Colonel Peter Lyle to Philadelphia to muster out 8/29
Artillery & Cavalry
2nd United States Artillery, Battery I at Fort McHenry
1st Maryland Cavalry Regiment Colonel Andrew G. Miller Organized at Baltimore