Benton's entire career was eminently creditable, and he is, besides, one of the most picturesque figures in American political history. His political principles--whether as regarded lobbying, congressional jobbing, civil service or great issues of legislation and foreign affairs--were of the highest. He was so independent that he had great dislike for caucuses, and despised party platforms--although he never voted any but the Democratic ticket, even when his son-in-law, J.C. Frémont, was the Republican presidential candidate in 1856; nor would he accept instructions from the Missouri legislature. His career shows no truckling to self-interest, and on large issues he outgrew partisanship. Although palpably inferior to each of his great senatorial colleagues, Webster, Clay and Calhoun, in some gifts, yet if character, qualities and career be taken in the whole his were possibly the most creditable of all. Benton was austere, aggressive and vain; besides, he had a fatal deficiency of humour. Nevertheless he had great influence, which was a deserved tribute to his ability and high character. An indefatigable student, he treated all subjects capably, and especially in questions of his country's history and the exploration of the West had few equals--in the latter none. He acted always with uncalculating boldness, and defended his acts with extraordinary courage and persistence. Benton wrote a _Thirty Years' View ... of the American Government_ (2 vols., 1854-1856), characteristic of the author's personality; it is of great value for the history of his time. He also compiled an _Abridgment of the Debates of Congress_, 1789-1850 (16 vols., 1857-1861), likewise of great usefulness; and published a bitter review of the Dred Scott decision full of extremely valuable historical details--_Historical and Legal Examination of ... the Dred Scott Case_ (1857). All were written in the last eight years of his life and mostly in the last three.
The best biography is that by W.M. Meigs, _Life of Thomas Hart Benton_ (Philadelphia and London, 1904). See also Theodore Roosevelt's _Thomas Hart Benton_ (Boston, 1887), in the "American Statesmen" series, which admirably brings out Benton's significance as a western man; and Joseph M. Rogers's _Thomas Hart Benton_ (Philadelphia, 1905) in the "American Crisis" series.