 Complete the following phrase:  Enlisting in the Union Army in May 1861, he received a commission as an officer with the 9th New York Volunteer Infantry Regiment, popularly known as Hawkins Zouaves, and later the IX Army Corps where he served under General Benjamin Butler at the Battle of Big Bethel and Hatteras Inlet expedition. In 1862, he accompanied the Army of the Potomac in General Ambrose Burnsides Roanoke expedition and took part in the Battles of Hatteras Inlet, 