The monument to the Oneida New York Cavalry Company is south of Gettysburg on Taneytown Road near Meade’s Headquarters at the Leister house. (39.814593° N, 77.232312° W; Google map; Tour map: Taneytown Road) It was dedicated in 1904 by the State of New York.
The company was commanded at the Battle of Gettysburg by Captain Daniel P. Mann. It brought 49 men to the field and suffered no casualties.
The Oneida Cavalry served at the headquarters of every general commanding the Army of the Potomac throughout the Civil War.
From the monument:
New York Cavalry
General Headquarters Escort
orderlies and couriers
Army of the Potomac
July 2 and 3 1863.