Born in Washington, Pennsylvania, McIlvaine received a Bachelor of Science degree from Washington & Jefferson College in 1928 and a Bachelor of Laws from the University of Pittsburgh School of Law in 1932.

He was in the United States Army Air Corps as a Lieutenant Colonel of the 7th Bomber Command during World War II.

[1] McIlvaine was nominated by President Dwight D. Eisenhower on March 20, 1955, to the United States District Court for the Western District of Pennsylvania, to a new seat created by 68 Stat.

He was confirmed by the United States Senate on July 29, 1955, and received his commission on August 1, 1955.

[1] McIlvaine served in that capacity until July 1, 1963, when he suffered a fatal heart attack in his chambers on the 6th Floor of the Pittsburgh Federal Courthouse.