Dickinson served as an officer during the American Revolutionary War, rising to the rank of Major General in the New Jersey Militia.

In January 1777 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.

While the attack was expected by Loyalist General Skinner and repulsed, Dickinson's party killed five and took 24 prisoners.

[1] Dickinson's militia took part in the Battle of Monmouth in 1778, helping obstruct the retreat of the British to New York.