[3] The beginning of the American Civil War interrupted Corson's education as he enlisted in Company K of the 4th Pennsylvania Infantry in April 1861, and mustered out as a sergeant in July 1861.

Returning to Penn late that year, he served as a medical cadet at the army hospital on Cherry and Broad Streets while studying at the school.

At Bristoe Station on 14 October, Corson and a hospital attendant rescued a severely wounded soldier left between the lines while under Confederate artillery fire.

He died on 24 July 1913 and his remains are interred at the West Laurel Hill Cemetery, Bryn Mawr section, Lot 98, in Bala Cynwyd, Pennsylvania.

With one companion returned in the face of the enemy's heavy artillery fire and removed to a place of safety a severely wounded soldier who had been left behind as the regiment fell back.