Gettysburg Union order of battle
Division Brigade Regiments and Others
First Division BG John Buford 1st Brigade Col William Gamble 8th Illinois Cavalry : Maj John L. Beveridge 12th Illinois Cavalry ( 4 companies ) and 3rd Indiana Cavalry ( 6 companies ) : Col George H. Chapman , Maj Charles Lemmon ( mw ) 8th New York Cavalry : Ltc William L. Markell
First Division BG John Buford 2nd Brigade Col Thomas Devin 6th New York Cavalry ( 6 companies ) : Maj William E. Beardsley 9th New York Cavalry : Col William Sackett 17th Pennsylvania Cavalry : Col Josiah H. Kellogg 3rd West Virginia Cavalry , Companies A and C : Cpt Seymour B. Conger
First Division BG John Buford Reserve Brigade BG Wesley Merritt 6th Pennsylvania Cavalry : Maj James H. Haseltine 1st United States Cavalry : Cpt Richard S. C. Lord 2nd United States Cavalry : Cpt Theophilus F. Rodenbough 5th United States Cavalry : Cpt Julius W. Mason 6th United States Cavalry : Maj Samuel H. Starr ( w ) , Lt Louis H. Carpenter , Lt Nicholas M. Nolan , Cpt Ira W. Claflin ( w )
Second Division BG David McMurtrie Gregg 1st Brigade Col John B. McIntosh 1st Maryland Cavalry ( 11 companies ) : Ltc James M. Deems Purnell ( Maryland ) Cavalry Legion , Company A : Cpt Robert E. Duvall 1st Massachusetts Cavalry : Ltc Greely S. Curtis 1st New Jersey Cavalry : Maj Myron H. Beaumont 1st Pennsylvania Cavalry : Col John P. Taylor 3rd Pennsylvania Cavalry : Ltc Edward S. Jones 3rd Pennsylvania Heavy Artillery , Section , Battery H : Cpt William D. Rank
Second Division BG David McMurtrie Gregg 3rd Brigade Col John Irvin Gregg 1st Maine Cavalry ( 10 companies ) : Ltc Charles H. Smith 10th New York Cavalry : Maj Mathew Henry Avery 4th Pennsylvania Cavalry : Ltc William E. Doster 16th Pennsylvania Cavalry : Ltc John K. Robison
Third Division BG Judson Kilpatrick 1st Brigade BG Elon J. Farnsworth ( k ) Col Nathaniel P. Richmond 5th New York Cavalry : Maj John Hammond 18th Pennsylvania Cavalry : Ltc William P. Brinton 1st Vermont Cavalry : Col Addison W. Preston 1st West Virginia Cavalry ( 10 companies ) : Col Nathaniel P. Richmond , Maj Charles E. Capehart
Third Division BG Judson Kilpatrick 2nd Brigade BG George A. Custer 1st Michigan Cavalry : Col Charles H. Town , Ltc Peter Stagg ( w ) 5th Michigan Cavalry : Col Russell A. Alger , Ltc Ebenezer Gould ( w ) , Maj Noah H. Ferry ( k ) 6th Michigan Cavalry : Col George Gray 7th Michigan Cavalry : ( 10 companies ) : Col William D. Mann
Horse Artillery 1st Brigade Cpt James M. Robertson 9th Michigan Battery : Cpt Jabez J. Daniels 6th New York Battery : Cpt Joseph W. Martin 2nd United States , Batteries B and L : Lt Edward Heaton 2nd United States , Battery M : Lt Alexander C. M. Pennington , Jr. 4th United States , Battery E : Lt Samuel S. Elder
Horse Artillery 2nd Brigade Cpt John C. Tidball 1st United States , Batteries E and G : Cpt Alanson M. Randol 1st United States , Battery K : Cpt William M. Graham , Jr. 2nd United States , Battery A : Lt John H. Calef
Army of the Potomac -- Cavalry Corps
MG Alfred Pleasonton Headquarter Guards : 1st Ohio Cavalry , Company A : Cpt Noah Jones ( Second Division ) 1st Ohio Cavalry , Company C : Cpt Samuel N. Stanford ( Third Division )
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.