He reported immediately to the Marine Detachment aboard the USS Alaska soon departing for the Far East.

During the punitive expedition to Korea, he took part in the assault on an enemy fort on the Han River.

Private Purvis ran immediately to the flagstaff which bore the Korean colors and loosed the halyards.

He was discharged in 1873 and served two additional tours with the Marine Corps, 1874 to 1879 and 1879 to 1884, rising to the rank of corporal.

Braving the enemy fire, Purvis was the first to scale the walls of the fort and capture the flag of the Korean forces.