He was called to active duty that May, attended Officer Candidates School and was commissioned a second lieutenant on July 18, 1942.

[1] In February 1946, he attended the Administrative School and was then assigned to Headquarters Marine Corps, where he served on the staff of G-4, Plans and Policies Division.

For his service in Korea, he was awarded the Legion of Merit with Combat "V."[1][2] After returning to the United States, he served as officer in charge, Marine Corps Recruiting Station, New York, from May 1954 until June 1956, during which time, in January 1955, he was promoted to lieutenant colonel.

From May 1963 until June 1964, he served with the 1st Marine Division at Camp Pendleton, California, as deputy G-4, logistics officer and later as assistant chief of staff, G-4.

In July 1964, he was assigned as deputy assistant chief of staff, G-4, Fleet Marine Force, Pacific in Hawaii.

From September to December 1968, General Snowden attended the Advanced Management Course of the Graduate School of Business at Harvard University prior to being assigned duty in the Office of the chief of staff as director of Management Analysis Group, which in February 1970, was re-designated the Systems Support Group.

For his service as the organizer and first director of the Systems Support Group, he was awarded a gold star in lieu of a fourth Legion of Merit.

[1][2] In June 1972, Major General Snowden was ordered to Tokyo where he served for three years as chief of staff, United States Forces Japan.

[1][2] Lieutenant General Snowden assumed the assignment of chief of staff, Headquarters Marine Corps, on May 21, 1977, and served in that capacity until his retirement on May 31, 1979.

[7] In 2016, he published his memoir, Snowden's Story: One Marine's Indebtedness to the Corps, recounting important events in his life that developed his character and philosophy.