Dickinson served as an officer during the
American Revolutionary War, rising to the rank of
Major General in the New Jersey Militia. At the beginning of the Revolutionary War in 1775 he was commissioned a
colonel of the
Hunterdon County militia. In 1776 he was elected as a delegate to New Jersey's Revolutionary provincial congress. Dickinson's Hunterdon militia led several successful attacks against British and
Hessian forces in late 1776. On January 20, 1777, during the
Battle of Millstone (also known as the ''Battle of
Van Nest's Mill''), Dickinson led 400 of his militia in a raid on a British foraging party near
Somerset Court House, New Jersey, capturing about forty wagons of supplies and several prisoners. In June 1777 he was appointed major general in command of all New Jersey militia, a post he held throughout the rest of the war. In November 1777 Dickinson led 1,400 men in a raid on
Staten Island. While the attack was expected by
Loyalist General
Skinner and repulsed, Dickinson's party killed five and took 24 prisoners. Dickinson took several
New Jersey Volunteers prisoner, including Lieutenant
Jacob Van Buskirk, Lieutenant Edward Earle and Surgeon John Hammell. Dickinson's militia took part in the
Battle of Monmouth in 1778, helping obstruct the retreat of the British to New York. When his cousin
John Cadwalader dueled General
Thomas Conway on July 4, 1778, Dickinson was Cadwalader's second. ==Post Revolution Public Service==