Goodwin was elected as a Whig to the Thirty-third Congress to fill the vacancy caused by the resignation of Gerrit Smith and served from November 7, 1854, to March 3, 1855. He was elected as a Republican to the Thirty-fifth Congress (March 4, 1857 – March 3, 1859).
He resumed the practice of law and died in Hamilton on November 12, 1860. He was interred in Hamilton's Madison Street Cemetery.