What political party did Chester A. Arthur belong to?

Chester A. Arthur was a Republican, but in office, he surprised many people by rising above political parties. He became the twenty-first president, assuming that position after the death of James A. Garfield. Arthur served as president from 1881 to 1885. He was a champion of civil service reform, and in 1883, he signed into law the Pendleton Act. This mandated that certain federal jobs were granted by merit, not political connections; that employees could not be fired for political reasons; and that a bipartisan Civil Service Commissions would be established to enforce the law. Arthur also signed into law the Tariff Act of 1883 and vetoed the Chinese Exclusion Act, but Congress overrode his veto. Due to health reasons, he did not seek re-election, and he was succeeded by Grover Cleveland.