 Hammond was a member and noted leader of the Georgia constitutional conventions in 1865 and 1877 that were tasked with creating a new state constitution.He also served as president of the board of trustees of the Atlanta College of Physicians and Surgeons.In 1878, Hammond won election to the United States House of Representatives and was re-elected for three more terms (1880, 1882, and 1884) before losing his seat in 1886 to John D. Stewart.