Before the Antietam Campaign:
Owner of a store in South Amboy, New Jersey (1851-57), he enrolled at age 37 in the Fifty-Seventh Infantry in New York City on 27 September 1861, and mustered as Major on 11 November. He was promoted Lieutenant Colonel on 18 July 1862 (ranking from February) to replace J.A. Page, who resigned - perhaps having never served with his unit.

In the Antietam Campaign:
He was in command of the regiment in Maryland, Colonel Zook being absent, ill.

"This regiment and the Sixty-sixth Regiment received orders to march on the enemy, who were at that time drawn up in a deep ditch at the foot of the hill on which we were, and from whence they were pouring a galling fire into our ranks. Animated by the presence of both their brigade and division commanders, the regiment moved forward with a determined enthusiasm I have never seen excelled. In a few minutes we had cleared the ditch of every living enemy, and were driving them in great disorder through the corn field beyond. It was during this period of the action that we lost our noble and gallant Lieutenant-Colonel Parisen and several valuable line officers.

We took the colors of the Twelfth Alabama and many prisoners. I am unable to form any very correct estimate of the number of the latter, but they considerably exceeded the number of men in the ranks of my regiment."

Maj. A. Chapman, who relieved LCol Parisen in command, in his official report

Phillip J Parisen