Spink was a member of the Illinois state House of Representatives in 1864, but moved to Yankton, Dakota in 1865, having been appointed as secretary of the territory, in which position he served until 1869. He was elected as a Republican to the House, and served from March 4, 1869 - March 3, 1871. He was an unsuccessful candidate for reelection in 1870, and returned to Yankton to practice law. He was again unsuccessful in 1876. He died in Yankton, and is intered in the City Cemetery there.