Gettysburg Union order of battle

The Union order of battle during the Battle of Gettysburg includes the American Civil War officers and men of the Army of the Potomac (multiple commander names indicate succession of command during the three-day battle (July 1–3, 1863)).
Order of battle compiled from the army organization during the battle, the casualty returns and the reports.
Army of the Potomac.
MG George G. Meade, Commanding
General Staff and Headquarters.
General Staff:
General Headquarters:
Command of the Provost Marshal General: BG Marsena R. Patrick 
Guards and Orderlies:
Engineer Brigade: BG Henry W. Benham 
I Corps.
MG John F. Reynolds (k) 
<br>
MG Abner Doubleday 
<br>
MG John Newton
<br>
General Headquarters: 
II Corps.
MG Winfield S. Hancock (w)
<br>
BG John Gibbon
<br>
BG William Hays
<br>
General Headquarters:
III Corps.
MG Daniel E. Sickles (w)
<br>
MG David B. Birney (w)
V Corps.
MG George Sykes
General Headquarters:
VI Corps.
MG John Sedgwick
General Headquarters:
XI Corps.
MG Oliver O. Howard 
<br>
MG Carl Schurz
General Headquarters:
XII Corps.
MG Henry W. Slocum 
<br>
BG Alpheus S. Williams
Provost Guard:
Cavalry Corps.
MG Alfred Pleasonton
Headquarter Guards:
Artillery Reserve.
BG Robert O. Tyler
<br>
Cpt James M. Robertson
Headquarter Guard: