As president of the United States from 1845 until 1849 James Knox Polk had a greater impact on American history than many of his counterparts did with twice the amount of time in that office. During his four years in the White House Polk redefined the nation’s boundaries through both negotiation and conquest. Though he avoided war with Great Britain over the border with Canada in the Pacific Northwest, Polk led the country into one with Mexico that ended with the annexation of over half a million square miles of territory. Yet while this territory would soon serve as a rich source of mineral wealth and a springboard for American trade in the Pacific, it also brought renewed controversy over the expansion of slavery that would end ultimately in civil war and emancipation.

As significant as Polk’s presidency proved, however, biographies of him are surprisingly scarce. This only adds to the value of Sam Haynes’s short account of his life and career. In just two hundred pages Haynes describes Polk’s early years, recounts his time in public office, and analyzes the factors that shaped the outcomes of his policies. It’s an extraordinarily efficient study that is no less insightful for its brevity, as he explains just how Polk came to have such an outsized impact on the nation’s history.

The son of a planter, as a young boy James Polk moved with his family from his North Carolina birthplace to the new state of Tennessee. With his physical activities limited by his poor health, Polk focused instead on academics and graduated first in his class from college less than three years after he arrived. Though he trained as a lawyer his passion was for politics, and within a few years he won a seat in the state legislature. Succeeding through hard work rather than charisma, he emerged as an early supporter of Andrew Jackson, and soon after his election to the House of Representatives he made a name of himself as one of “Old Hickory’s” staunchest supporters.

While Polk became Speaker of the House at the age of 40, his sights were set higher still. It was to demonstrate his value on a national ticket that he gave up his seat in Congress in 1839 in favor of the governorship of Tennessee. Polk served just a solitary two-year term before he was defeated for reelection and again when he tried to reclaim his office. While Polk still entertained hopes that he might be selected to provide regional balance as Martin Van Buren’s running mate in 1844, Van Buren’s waffling on the issue of Texas annexation cost him the nomination of the expansionist Democratic Party, which turned to the Jackson-endorsed Polk as the nominee.

As Haynes demonstrates, the man had met the moment. Polk became president at a time a fever for westward expansion had seized the imagination of millions of Americans. Polk was elected with the promise not just to annex Texas but to expand the nation’s borders everywhere possible. Though Polk did so through different means, Haynes sees the same common course of action behind his handling of the crises with both Britain and Mexico: namely the adoption of a bellicose posture with little room for compromise. That it led to a peaceful settlement with one and war with the other reflected the differing positions of the two nations, with Mexico’s political instability denying them the luxury of being able to brush off Polk’s brinksmanship.

The result was a war that created a new set of problems for the president. Haynes portrays Polk as a micromanager attempting to direct the war from the White House. This soon led to conflict with his leading generals, whom Polk worried could become Whig presidential candidates. These concerns only grew as public opinion in many parts of the country shifted in favor of the Whigs, whose gains in Congress jeopardized his ability to continue the war. Though he attempted to recall his own peace envoy, Polk was forced to accept the Treaty of Guadalupe Hidalgo out of a fear that further Whig electoral victories might result in a settlement without any territorial annexations. With the acquisitions secured by the Senate’s ratification of the treaty Polk left office with his goals accomplished, though at the cost of having exhausted himself to such an extent that he was left vulnerable to an outbreak of cholera just a few months after his presidency ended.

The requirements of the Library of American Biography series placed a premium on economy. This results in the case of this book is a highly efficient text that touches on all of the key details of Polk’s time in office. Though Haynes includes a short chapter that describes Polk’s economic and fiscal policies, his focus is on the expansionist program that was the most important aspect of Polk’s presidency. Yet Haynes also finds the space provide a succinct analysis of Polk’s personality, giving his readers a good sense of what he was like and how that defined his strengths and weaknesses as a public figure. The result is a fine concise study of Polk’s life that is a good place to start for anyone seeking an introduction to this president and his sometimes underappreciated significance. ( )