At the start of the American Revolutionary War he rallied to the patriot cause and was appointed lieutenant colonel of a New Jersey state regiment.

At the time of the battles of Trenton and Princeton Forman's regiment waged a merciless war against the American Loyalists of Monmouth County.

When local guides failed to appear on time, he directed the vanguard on the correct route.

He organized a system of outposts on the coast in 1780 that reported British and French ship movements.

The dying man took a ship home but it was captured by a British privateer and brought into The Bahamas where he succumbed on 12 September 1797.