Knowlton was born in Canandaigua, New York, in 1813.[1] His brother and parents moved to the Wisconsin Territory in the 1830s, and he joined them at Janesville in 1838.[2] He was there only briefly before moving to Mineral Point, and in 1847, he moved to Shullsburg, in Lafayette County.[1] At Shullsburg he completed his legal studies, was admitted to the bar, and served as the first probate judge of the county.[1]
Political career
He was a member of the legal team defending Judge Levi Hubbell during his 1853 impeachment, and later that year was elected to the Wisconsin State Assembly as a Democrat. He was not reelected in 1854, but was returned to office again in 1856, this time as a Republican. Following the 1855 election, however, Knowlton became involved in Republican gubernatorial candidate Coles Bashford's legal challenge of the election results. Bashford ultimately prevailed and took office in March 1856.[1]
After the 1856 legislative session, Knowlton moved back to Janesville, in Rock County, where he was elected to his third and final Assembly term in 1857.[1]