 As commanding officer of 70th New York Volunteer Infantry Regiment, Dwight led his regiment during the Battle of Williamsburg, where he was seriously wounded on May 5, 1862, along with losing half of his command.Left for dead on the battlefield, Dwight was found by Confederate forces and held as a prisoner of war until his eventual release in a prisoner exchange November 15, 1862.In recognition of his gallantry on the field, Dwight was promoted to brigadier general of volunteers to rank from November 29, 1862, by Presidential nomination on March 4, 1863, and U.S. Senate confirmation on March 9, 1863.