David McMurtrie Gregg
David McMurtrie Gregg was a farmer, diplomat, and a Union cavalry general in the American Civil War.
Gregg was born in Huntingdon, Pennsylvania. He was the first cousin of future Pennsylvania Governor Andrew Curtin and the grandson of Pennsylvania Congressman Andrew Gregg. He graduated from the United States Military Academy in 1855 and was given a commission as a brevet second lieutenant in the 2nd U.S. Dragoons Regiment . During his tenure at West Point, he interacted with two classmates who would become great cavalry generalsan opponent and a commander, respectively J.E.B. Stuart, class of 1854, and Philip Sheridan, class of 1853.
Source: Wikipedia