Upon graduation, he was commissioned as a second lieutenant in the Marine Corps and subsequently attended the Basic School in Philadelphia, Pennsylvania.

In March 1941, he was given command of the Marine detachment aboard the USS North Carolina, and was promoted to major in May 1942.

Tschirgi was assigned to the 1st Marine Division in July 1944, and took part in the battle of Peleliu from September to October, where he was awarded the Bronze Star.

In June 1949, Tschirgi was assigned to the Naval War College in Newport, Rhode Island.

In October 1952, he was sent to Korea and was assigned to the 1st Marine Division in November, ultimately taking command of the Kimpo Provisional Regiment on December 1.