Born in Rockville, Connecticut, to a Polish immigrant family,[1] Sadlak attended the parochial school.

He served as assistant secretary-treasurer of the Farmers' Production Credit Association, Hartford, Connecticut, from 1944 to 1946.

He served in the United States Naval Reserve in New Guinea, the Philippines, and China from March 1944 to April 1946.

After his Congressional career, he served as regional assistant manager for the Veterans' Administration, Hartford, Connecticut, from March 30, 1959, to May 2, 1960.

This article incorporates public domain material from the Biographical Directory of the United States Congress