He was born in Compton, Lower Canada in 1827. The families of his parents had come to the Eastern Townships from New England. He studied law with John Sewell Sanborn and was called to the bar in 1853. There was a surplus of lawyers at the time, so he became a merchant to provide himself with additional income. He also established a newspaper in Knowlton, later moving it to Waterloo after he was hired as secretary for a railroad company based there. He ran for the Shefford seat in the Legislative Assembly in 1860, but the election was not settled before parliament was dissolved; he was elected in the election that followed in 1861. In 1863, he was appointed solicitor general for Canada East. During the American Civil War, he profited from his ownership of a copper mine; later, the market in copper collapsed and so did Huntington's profits.
In 1873, he exposed the Pacific Scandal which led to the fall of Sir John A. Macdonald's Conservatives. He then became part of a syndicate formed to continue construction of the railway. He intended to resign from his government post to enter this business venture, but was persuaded to remain in office when the Conservatives alleged wrongdoing in his sale of his interests in copper mines, since his resignation might be interpreted as a sign of guilt. In 1875, Huntington was heavily criticized for a speech where he advised English Protestants in Quebec to vote Liberal to protect their own interests versus those of French Catholics. He fell ill later in his parliamentary career and, after his defeat in 1882, moved to New York City to seek medical treatment.