 In 1972, Mitchell was elected to the United States Congress where he represented what is now New York's 31st Congressional District.After being successfully re-elected to a second term by a wide margin in 1974, he then ran unopposed to for three more terms, serving in Congress a total of 10 years from January 3, 1973 until January 3, 1983.While in the U.S. Congress, Mitchell served on the House Armed Services Committee, and was elected by his colleagues and served four years in the House Republican Leadership as Regional Whip for New England and the Mid-Atlantic States.