 He was general counsel for the Wage and Hour Division of the United States Department of Labor from 1938 to 1939.Magruder was nominated by President Franklin D. Roosevelt on April 24, 1939, to a seat on the United States Court of Appeals for the First Circuit vacated by Judge George Hutchins Bingham.He was confirmed by the United States Senate on June 1, 1939, and received his commission on June 3, 1939.