He was a lieutenant in the United States Navy during World War II, from 1942 to 1945.
He was a judge of the Eighth Judicial Circuit Court of Missouri from 1949 to 1962.
[1] On March 5, 1962, Regan was nominated by President John F. Kennedy to a seat on the United States District Court for the Eastern District of Missouri vacated by Judge Randolph Henry Weber.
He was a Judge of the Temporary Emergency Court of Appeals from 1977 to 1987.
He assumed senior status on April 7, 1977, serving in that capacity until his death on March 9, 1987.