During the First World War served as a captain and was promoted to major in the 342nd Infantry, 86th Division from 1917 to 1919.
After the war, he resumed the practice of law at Chicago, Illinois and engaged as an investment banker in 1921.
He served as an alderman in Evanston, Illinois from 1931 to 1937 and as park commissioner 1929–1931, 1937, and 1938. He served as delegate to the Republican State convention in 1936 and also as member and treasurer of Cook County Republican Central Committee from 1938 to 1942.
He also served as member of the Soldiers' and Sailors' Service Commission of Illinois.
Paddock was elected as a Republican to the Seventy-seventh Congress (January 3, 1941 – January 3, 1943). He was an unsuccessful candidate for renomination in 1942 and resumed investment banking.