Born in Hampshire County, Massachusetts, June 6, 1800. His boyhood was spent on his father's farm where he attended district school during the winter months until he acquired sufficient education to teach in the common schools. He entered Amherst College and, taking the classical course, graduated. He then went to Virginia and engaged in teaching, earning money enough to support himself while pursuing his law studies. He was admitted to the bar in Pickens County, Alabama, where he had decided to locate. In 1834 he was elected to a seat in the House of the Alabama Legislature, serving three terms. He removed to Tuscaloosa, then the Capital of the State, in 1836, and in 1839 was appointed Attorney-General. In 1846 he was appointed judge of the United States Circuit Court. He came to Iowa in 1848, locating in Dubuque, where in 1852 he was chosen one of the presidential electors on the Democratic ticket, casting his vote for Franklin Pierce for President. In 1850 he received the nomination for Congress in the old Second District which at that time embraced more than half of the State. His competitor on the Whig ticket was John P. Cook of Davenport. The contest was close, but Clark was elected by the narrow margin of but one hundred fifty in a total vote of 15,696. At the close of his term the same candidates renewed the contest but Cook won the election. In 1857 Mr. Clark was elected to the House of the Seventh General Assembly and gave the State valuable service in adapting the laws to the new Constitution. He was a life-long Democrat.