Adam Stephen was a Scottish-born American doctor and military officer who helped found what became Martinsburg, West Virginia. He emigrated to North America, where he served in the Province of Virginia's militia under George Washington during the French and Indian War. Stephen entered Royal Navy as a surgeon (with possible rank of Lieutenant) after completing medical studies in 1746 and served on a hospital ship during the Siege of Lorient before emigrating to the British colony of Virginia in 1748. Stephen joined the provincial troops in 1754 and became lieutenant colonel of the Virginia Regiment under George Washington. While Captain Charles Lewis escorted 60 former settler prisoners back to Fort Pitt in 1764, Stephen had assumed command of the Virginia Regiment from Washington and traveled westward to assist in putting down Pontiac's Rebellion.

When the American Revolutionary War broke out, Stephen offered his services to the Continental Army, again serving under Washington. He was with the army during the New York and New Jersey campaigns of 1776 and early 1777, and as a major general he was given command of a division in Washington's army during the defense of Philadelphia. In the October 1777 Battle of Germantown, Stephen's men fought in the fog with troops led by General Anthony Wayne. Stephen was accused of being drunk during the battle, and after being convicted in a court martial, he was stripped of his command and cashiered out of the army, making him the only Continental Army general court-martialed and immediately dismissed from the service during the war.