In his own time, Thomas Hart Benton was always a force to be reckoned with. But the Missouri Democrat who served nearly 30 years in the Senate has not received the love or attention from historians that some of his more celebrated contemporaries enjoy.

Ken S. Mueller sets out to rectify that omission in “Senator Benton and the People: Master Race Democracy on the Early American Frontiers,” and to a great degree — although not wholly — he succeeds.

Benton served Missouri in the Senate from the time of statehood in 1821 until he was unceremoniously tossed out of office in 1850, largely over his refusal to support the extension of slavery. (He served one term in the House, then lost again, and lost a race for governor in 1856.) A century later, his principled stand won him plaudits from John F. Kennedy, who accurately described Benton in “Profiles in Courage” as “a rough and tumble fighter off and on the Senate floor.”

But such praise was of little use to Benton when he was alive, and it has been rare enough since.

Benton was never nominated for president and was most certainly not a great compromiser like Henry Clay, whose inveterate desire to split the difference has endeared him to generations of historians and Solomonic moderates.

He was a stentorian speaker, but not a razor sharp wit, a classic phrasemaker or a lawyerly debater in the manner of Daniel Webster. Benton’s arguments were often arcane, he tended toward long-windedness and had what Mueller calls a “penchant for the melodramatic.”

While later in his career he firmly opposed the extension of slavery into the territories at a time when no other slave-state Democrat would, he was not the leader of a bloc, as was John C. Calhoun. Benton was a bloc of one.

A Representative Man

Benton’s career was more like that of a modern senator than any of the Great Triumvirate. While Clay, Webster and Calhoun moved in and out of Congress as they took executive branch positions, Benton remained a creature of the Senate.

But Benton was a more representative figure of his era than Clay, Webster, Calhoun or any other man in Congress. His “early life may be understood as a narrative of migration from one American ‘West’ to another,” Mueller writes. Beyond that, Benton’s entire life story could serve as a stand-in for the story of America itself: Born in the East, he migrated over the mountains to Tennessee, where he became first a friend and then a foe of Andrew Jackson — the two engaged in a barroom gun and knife fight in which both were wounded — then on to Missouri, always with one eye cast even further west, and an evolving ambivalence about slavery, even as he owned slaves and stood fast in defense of white supremacy.

Benton’s role as a hinge figure in the debates over burgeoning democracy and western expansion, and how each affected debates over race and slavery, form the heart of Mueller’s book.

Central to his thesis is the geographical fact of Missouri sitting at two crossroads, between North and South, and between East and West. Benton, who came from middle privilege and began his Missouri career as a lawyer for the ruling class, saw the Jacksonian writing on the wall and mutated into a tribune for the growing class of farmers and workers who, like Benton, began pouring into Missouri in the 1810s. His dedication to hard money and his wariness of Eastern financial interests earned him the nickname Old Bullion.

The vociferous role Benton played in the debates over Texas annexation, the Mexican War and the Compromise of 1850 are fully recounted. Always, like Jackson, he put national interests over sectional concerns. He was perfectly willing to protect slavery and annex Texas, but not at the risk of disunion. Unlike Jackson, who died in 1845 just as the debate over slavery began to heat up, Benton’s dedication to the Union cost him everything.

The Missourian’s lifelong devotion to the Democratic Party outlasted its devotion to him. Even after the party threw him over for slavery, Benton refused to abandon it and supported the weak-willed James Buchanan against his own son in law, John C. Fremont, in the 1856 presidential contest.

“That lonely old man,” as his daughter Jessie called him in the winter of 1855-56, was again a living reflection of his country — untethered from what had gone before, both Benton and the nation searched desperately for answers, but found none.

The thematic and academic nature of Mueller’s writing steers him clear of the central non-political drama of Benton’s story — his close but tempestuous relationship with daughter Jessie Benton Fremont, a formidable figure in her own right. It’s a noticeable absence and lessens the appeal of the book for the general reader.

At times the prose devolves into dissertationese, particularly when discussing dueling and the “affairs of honor” that so often prevailed in the early republic; a pastime with which Benton had more than a passing familiarity. This is understandable, since the book began as Mueller’s doctoral dissertation, but the digressions often go on longer than necessary.

But these are mostly quibbles. In the more than half century since the last full-length biography of Benton was published, a revolution has taken place in how historians and the general public view the early American republic. Benton’s central role in the debates of those days deserves a fresh look, and Mueller gives us a full and balanced political portrait of the man who, more than any other figure of his time, embodied the aspirations and contradictions at the heart of the American experiment.

John Bicknell is a former editor at CQ Roll Call and author of “America 1844: Religious Fervor, Westward Expansion and the Presidential Election That Transformed the Nation,” to be published in November by Chicago Review Press. Connect with him on Twitter @johnbick1960.