Born in
St. Louis,
Missouri, McMillian attended
Vashon High School. He received a
Bachelor of Science degree from
Lincoln University in 1941. He received a
Bachelor of Laws from
Saint Louis University School of Law in 1949. He was in the
United States Army from 1942 to 1946. He was in private practice of law in St. Louis from 1949 to 1953. He was an assistant circuit attorney of City of St. Louis from 1953 to 1956. He was a judge of the Circuit Court in St. Louis from 1956 to 1972. He was appointed by Governor
Warren E. Hearnes as a judge of the Eastern Division of the
Missouri Court of Appeals from 1972 to 1978, being retained in 1974. He was an associate professor at the University of Missouri from 1970 to 1972. He was a faculty member of the National College of Juvenile Justice at the
University of Nevada, Reno from 1972 to 1977. He was an associate professor of the
Webster College Graduate Program in 1977.
Other service McMillian served as board chairman of the Human Development Corporation, local CAP agency, Minority Economic Development Agency and the Herbert Hoover’s Boys Club of St. Louis. He served as a board member of the American Judicature Society, Blue Cross Hospital Association and Urban League. He was a member of the St. Louis University’s President’s Council and board of trustees of the St. Louis Junior College District. ==Federal judicial service==