 He was in private practice in St. Louis, Missouri from 1902 to 1935, also working as a United States Collector of Internal Revenue from 1914 to 1922.Moore was nominated by President Franklin D. Roosevelt on May 20, 1935 to a seat on the United States District Court for the Eastern District of Missouri vacated by Judge Charles Breckenridge Faris.Moore was confirmed by the United States Senate on May 28, 1935, and received his commission the following day.