In 1854 there was a vacancy for the
Legislative Council of Nova Scotia, and the
Cape Breton News, a paper on Cape Breton Island, campaigned for the seat to be filled by someone from the island. Archibald was appointed later that year, remaining on the council until 1867, and was its chairman in 1861. He became involved with the termination of General Mining Association's monopoly in Nova Scotia in 1858 and 1859. He advocated for residents on
Cape Breton Island to continue to mine for coal on their property after the end of the monopoly. This event also allowed other firms, such as Archibald's Gowrie Mines, to open new coalfields on the island. Archibald opposed bills that would equalize the electoral weight of counties in Nova Scotia and allow French fishermen, subsidized by their government to sell their products duty-free. He also opposed increasing the penalties for violating liquor licensing laws, stating sarcastically, "we need only go a step further and make the violation a hanging matter." He was affiliated with the
Liberal-Conservative Party. He was also appointed as the United States Consul in Sydney. ==Personal life and death==