James K. Polk appears doomed to remain one of our least-appreciated presidents, despite Robert W. Merry’s valiant attempt to drag him from the shadows in A Country of Vast Designs. The problem lies with Polk himself, a man who even Merry concedes was “drab of temperament,” with “limited imagination,” and lacking in “natural leadership ability.” He was affectless, narrow-minded, and difficult, but so are many great national leaders.

Yet Polk could count himself a successful president indeed. When he left office in 1849—fulfilling a promise to serve only one term—he had stared down Britain into defining the boundaries of the Oregon Territory and waged a war with Mexico that, however bitterly challenged, conquered more than half a million square miles of the Southwest. In so doing, Merry writes, “Polk brought to his presidency imperatives of boldness, persistence, force of will, and guile that went beyond anything anyone had seen before in him.”

Born in North Carolina in 1795, Polk moved to Tennessee with his family in 1806. There, he studied law and fell under the influence of his family’s friend Andrew Jackson, who persuaded him that marriage would solidify his local standing and suggested Sarah Childress. It was a happy marriage, although childless, probably because of a horrendous operation for urinary stones Polk underwent in his teens.

As a congressman and later Speaker of the House, Polk became an important ally of President Jackson, whose Democratic principles of limited government stood in contrast to the Whig Henry Clay’s mercantilist “American System.” Polk became especially important to Old Hickory during Jackson’s contest with the Second Bank of the United States.

Polk then served as governor of Tennessee, but was defeated for reelection in 1841. It appeared that his time had passed—until Texas reshaped the political landscape. The young republic had won its independence from Mexico in 1836, and popular American sentiment favored incorporating it into the Union. In 1844, the anticipated Democratic nominee Martin Van Buren crippled his chances by announcing his opposition to such a measure. At the Democratic convention, Polk emerged as a triumphant dark horse and then defeated Clay to become president.

Polk set four major goals—settling the boundaries of Oregon, taking California from Mexico, lowering heavy tariff rates, and establishing an independent treasury—and accomplished them all. “Probably no other president presents such a chasm between actual accomplishment and popular recognition,” as Merry observes. Today we might label Polk a workaholic and a control freak. If the president did attend a social occasion, Merry notes, he would make up for it by working extra the next day.

“He was in many ways a smaller-than-life figure, but he harbored larger-than-life ambitions,” writes Merry. On Oregon, jointly occupied by the United States and Britain, Polk maintained a “stoic stubbornness” until he got the border he wanted, despite occasional vexing iniatives from his slippery and ambitious secretary of state, James Buchanan. Questions about the Texas border (the republic had joined the United States just as Polk took office) inflamed