He began his military career during World War I, enlisting in the Aviation Section of the United States Army's Signal Corps in 1918.

After World War II, Finch was a leading critic of efforts to eliminate the air arm of the National Guard during peacetime.

Under his leadership, the Air National Guard built to combat readiness and was among the first components called into service after the outbreak of the Korean War.

As a result of Finch's vision and perseverance, 45,000 officers and airmen of 22 wings and 65 squadrons gave the Air Force the strength it needed in the early phase of the Korean War.

Finch served as the senior Air Force member of the United Nations negotiating team at the peace talks at Panmunjom, Korea, and received the Legion of Merit for outstanding service in 1955.