A monument and a tablet  for the Reserve Brigade, 1st Division, Cavalry Corps are on Emmitsburg Road on the South Cavalry Field.

Monument to the Reserve Brigade of the 1st Cavalry Division, Cavalry Corps, Army of the Potomac on the Gettysburg battlefield

Army of the Potomac 
Cavalry Corps First Division 
Reserve Brigade 
Brig. Gen. Wesley Merritt
6th Pennsylvania
1st 2d 5th 6th United States Cavalry

July 1. Engaged in picketing and patrolling the roads through the mountains detachments scouting the country about Hagerstown Cavetown and other points.

July 2. Marched to Emmitsburg Md.

July 3. At noon marched four miles on the road to Gettysburg met Confederate detachments and for more than a mile drove them from stone fences barricades and other positions being engaged four hours and until the operations were brought to a close by heavy rain. The 6th United States under Major S. H. Starr was detached and marched towards Fairfield to intercept a Confederate wagon train supposed to be in that vicinity but encountered a superior force and was compelled to fall back with heavy loss.

Casualties Killed 1 Officer 27 Men
Wounded 12 Officers 104 Men
Captured or Missing 6 Officers 268 Men Total 418

Marker for the Reserve Brigade of the 1st Cavalry Division, Cavalry Corps, Army of the Potomac on the Gettysburg battlefield

The monument to Battery K, 1st United States Artillery can be seen in the distance on the left.

From the tablet:

Position of the
Reserve Brigade
First Division Cavalry Corps
1-2-5-6 U.S. Cavalry
and
Battery K 1st U.S. Artillery