Third Army Corps

Major General Samuel P. Heintzelman

The death of Kearney at the Battle of Chantily and the transfer of Hooker to command the First Corps changed both division commanders. The corps was assigned to the Washington Defenses during the Maryland Campaign and missed the Battle of Antietam.

First Division

Bde. Gen. Philip Kearney (k 9/1)

Bde. Gen. David Birney (9/1 - 9/13)

Bde. Gen. George Stoneman (after 9/13)

1st Brigade

Bde. Gen. John C. Robinson

2nd Brigade

Bde. Gen. David B. Birney (9/1 & after 9/13)

Colonel J. H. H. Ward (9/1 - 9/13)

3rd Brigade

Colonel Orlando Poe

Brigadier General H. G. Berry

Second Division

Bde. Gen. Joseph Hooker (until 9/5)

Bde. Gen. Daniel E. Sickles

1st Brigade

Brigadier General C. Grover (until 9/16)

Brigadier General J. B. Carr

2nd Brigade

Colonel Nelson Taylor (until 9/5)

Colonel George B. Hall

3rd Brigade

Bde. Gen. F. E. Patterson

Artillery

1st New York Artillery, Battery D

6th New York Independent Battery