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Cavalry forces played a significant role at Gettysburg only on the first and third days of the battle. On the first day (July 1, 1863), the Union cavalry division of Brig. Gen. John Buford successfully delayed the Confederate infantry forces under Maj. Gen. Henry Heth until Union infantry could arrive on the battlefield. By the end of the day, Buford's troopers had retired from the field.[1]

On the Confederate side, most of Maj. Gen. Stuart's cavalry division was absent from the battlefield until late on the second day. Possibly misunderstanding orders from General Robert E. Lee, Stuart had taken his three best brigades of cavalry on a pointless ride around the right flank of the Union Army of the Potomac and was out of touch with the main body of Lee's Army of Northern Virginia since June 24, depriving Lee of critical intelligence information and of screening services. Stuart arrived from Carlisle at General Lee's headquarters shortly after noon on July 2, and his exhausted brigades arrived that evening, too late to affect the planning or execution of the second day's battle. Hampton's Brigade camped to the north, following the relatively minor clash with Union cavalry at Hunterstown that afternoon.[2]

Lee's orders for Stuart were to prepare for operations on July 3 in support of the Confederate infantry assault against the center of the Union line on Cemetery Ridge. Stuart was to protect the Confederate left flank and attempt to move around the Union right flank and into the enemy's rear. If Stuart's forces could proceed south from the York Pike along the Low Dutch Road, they would soon reach the Baltimore Pike, which was the main avenue of communications for the Army of the Potomac, and they could launch devastating and demoralizing attacks against the Union rear, capitalizing on the confusion from the assault (Pickett's Charge) that Lee planned for the Union center.[3]

Confederate cavalry forces under Stuart for this operation consisted of the three brigades he had taken on his ride around the Union Army (commanded by Brig. Gen. Wade Hampton, Brig. Gen. Fitzhugh Lee, and Colonel John Chambliss) and the brigade of Col. Albert Jenkins (under the command of Col. Milton J. Ferguson following Jenkins's wounding on July 2). Although these four brigades should have amounted to approximately 5,000 troopers, it is likely that only 3,430 men and 13 guns saw action that day.[4] And following their nine-day ride around Maryland and Pennsylvania, they and their horses were weary and not in prime condition for battle.[5]

Union cavalry forces were from the corps of Maj. Gen. Alfred Pleasonton, who did not participate directly in the command of any cavalry actions during the Battle of Gettysburg. Since most of Buford's division had retired to Westminster, Maryland (with the exception of his reserve brigade under Brig. Gen. Wesley Merritt, which was deployed directly south of Gettysburg), only two divisions were ready for action. Stationed near the intersection of the Hanover Road and the Low Dutch Road—directly on Stuart's path—was the division of Brig. Gen. David McM. Gregg. Gregg had two brigades present at Gettysburg, under Col. John B. McIntosh and Col. J. Irvin Gregg (David Gregg's cousin), but the latter was stationed on the Baltimore Pike. Irvin Gregg's one-brigade command was supplemented by the brigade of Brig. Gen. George Armstrong Custer. Custer was assigned to the division of Brig. Gen. Judson Kilpatrick but happened to be on loan to David Gregg and requested permission from Gregg to join his fight. Altogether, 3,250 Union troopers opposed Stuart. The other brigade from Kilpatrick's division, commanded by Brig. Gen. Elon J. Farnsworth, was stationed to the southwest of the Round Top mountain, the area now known informally as South Cavalry Field.[6]