Civil War Union Army Officer. He volunteered as a private in the 12th regiment, New York state militia., which was one of the three that first started from New York for the seat of war. In August 1861, he was commissioned second lieutenant in the 4th regular infantry. In March 1862, he embarked for the peninsula, and through the battles of the Potomac army was conspicuous for gallantry. At Fredericksburg he commanded forty men of the strong picket-line that, during the night of 13 December 1862, was pushed up to the enemy's position, while the defeated federals were retreating across the river. The orders were to hold the position until relieved, and the intention was to withdraw the picket-line before daylight should reveal it to the enemy. By some mistake the line was not withdrawn as directed, and at daylight the enemy opened fire at short range. While encouraging his men by voice and example, Major Benedict fell, shot through the lungs, but was carried off the field by his soldiers. The wound was considered mortal, but, before the scar was fairly healed, in three months, he reported for duty at Washington. He joined his regiment at Chancellorsville while the battle was in progress. At Gettysburg his superiors were all killed or wounded, leaving him in command, and he handled the regiment during that battle with great credit to himself. Shortly after Gettysburg his health began to fail, as a result of his wound; but in spite of this he refused to give up active service, and for some time commanded the 4th infantry, as General Grant's headquarters guard during the Petersburg campaign. After the war he remained on the active list in spite of his disability from his wound, and in the depth of winter, shortly before his death, was on duty at Plattsburg, New York, one of the coldest of the eastern army posts. He secured a change of station in the hope of benefit from a warmer climate, but died from the effects of the wound received five years before.

Promoted to Full 1st Lieutenant.
Commission in 4th Infantry Regiment Regular Army on 5 Aug 1861.
Enlisted as a 2nd Lieutenant on 5 August 1861.
Promoted to Brevet Captain on 27 Jun 1862.
Promoted to Brevet Major on 13 Dec 1862.
Promoted to Full Captain on 8 Jun 1863.
Died of disease 4th Infantry Regiment Regular Army on 15 May 1867.