 In 1876, he was elected as a Republican from Michigan's 4th congressional district to the 45th United States Congress, serving from March 4, 1877 to March 3, 1879.Keightley was appointed by U.S. President Rutherford B. Hayes as the Third Auditor of the United States Treasury Department and served from April 30, 1879 to April 30, 1885, when he resigned.He resumed the practice of his profession in Chicago, Illinois.