Dunbar was elected as a
Republican to the
Sixty-sixth and
Sixty-seventh Congresses (March 4, 1919 – March 3, 1923). He was not a candidate for reelection in 1922. Dunbar was elected to the
Seventy-first Congress (March 4, 1929 – March 3, 1931). He was an unsuccessful candidate for reelection in 1930 to the
Seventy-second Congress. He resumed his former business pursuits. ==Death and burial==