Born in Detroit, Michigan, on September 15, 1913. His education included Fordham University from 1932 to 1934, an LL.B. degree from Fordham in 1938, and postgraduate study at St. John's University Law School in 1938 and 1939. He was admitted to the New York State bar in 1938. Mitchell was an associate in the law firm of Caldwell and Raymond from 1938 to 1942. He served in the United States Navy during World War II and then became a partner in the law firm of Caldwell, Trimble and Mitchell from 1942 to 1966, and a partner in the law firm of Nixon, Mudge, Rose, Guthrie, Alexander and Mitchell from 1967 to 1968. He was a member of the American Bar Association. President Richard M. Nixon appointed Mitchell Attorney General of the United States on January 21, 1969. He served in that capacity until February 15, 1972, when he resigned to head the committee for the reelection of President Nixon. He died November 9, 1988.