Updated: Nov. 17, 9:43 a.m.

“Who is James Polk?—

That isn’t just a question posed to reveal modern-day ignorance. In the presidential election battle of 1844, these words were a campaign slogan. Supporters of Whig nominee Henry Clay transformed the question into a chant of condescension against his Democratic opponent, James Polk.

On the face of things, the Whigs had some reason for cockiness. Polk had been plucked from political oblivion as the Democrats’ nominee. At the time, Polk was a double failure, having lost successive bids in 1841 and 1843 for re-election to Tennessee’s governorship.

But at the end of the day, the Tennessean would capture the presidency by a 39,490-vote margin out of 2,703,659 votes cast. Even with a slim victory, it was Polk who proved the naiveté of his opponents’ calculus.

Underestimation seems be a recurring hallmark of the country’s 11th president. Even with time, Polk’s true legacy remains to be seen. He is still often assumed just to be one of “those guys— before the great Abraham Lincoln.

But one of the many merits of Robert Merry’s new book, “A Country of Vast Designs,— is to reveal the foolhardiness of that assumption. Merry was until recently the longtime editor in chief of Congressional Quarterly.

Merry writes the biography in an engaging manner and with great detail, and in the process works to shed light on Polk’s life.

In fact, Polk had a transformative effect on the country’s direction. Simply look at a map of the United States: Before Polk took office, the region that today takes up Texas, California and Oregon did not belong to the United States. In just one term, Polk succeeded in completing the annexation of Texas from Mexico; acquired the land that today makes up California, Nevada, Utah and Arizona; and acquired the Oregon territory, otherwise known as present-day Idaho, Oregon and Washington.

Merry lays out Polk’s life in blocks and in chronological order. Raised in Tennessee, Polk was a lawyer who became a protégé of fellow Tennessean Andrew Jackson. Polk won election to Congress in 1825, and under Jackson’s influence he shot to prominence. In no small part because of his own legislative brilliance, Polk became chairman of the Ways and Means Committee and then Speaker of the House in a span of 10 years.

Even with Jackson’s help, Polk was ever shrewd on his own behalf. One of the more revealing examples was Polk’s delicate walk to secure his party’s nomination in 1844. After twice failing to regain the Tennessee governorship, he set his sights on the Democrats’ vice presidential nomination. With party dissatisfaction over presumed nominee Martin Van Buren, Polk successfully maneuvered into the top spot by ingratiating himself to other Democrats before the 1844 Baltimore convention.

Upon taking the office of presidency in March 1845, Polk privately laid out two goals of territorial expansion: “to settle the Oregon question with Great Britain and to extend America to the Pacific Ocean. Second, he would acquire California from Mexico.—

Polk fulfilled his goals and in the process successfully beat back Mexico in war. Merry shows Polk’s pursuit of the Mexican War to be more nuanced than often portrayed in hindsight. In the context of expansionist fervor of the United States, Mexico’s goading with a first attack in May 1846 was understandably met with war. By September 1847, Mexico was brought to defeat with the American occupation of Mexico City.

Merry’s account is hardly a hagiography, however. He notes Polk’s deficiencies, which included considering slavery “a side issue, something that just got in the way of important political objectives.— Some historians like to draw parallels between Richard Nixon and Polk on several accounts, not the least of which included dogged determination in the pursuit of clear goals. Polk ignored the slavery diversion perhaps perilously, but he ultimately accomplished what he set out to do.

Merry’s account is well-sourced with extensive use of primary accounts to detail the president’s life. That strong research pays off in other charms, such as Merry’s portraits of supporting characters. Great depth is given to various characters surrounding Polk, including to his wife, Sarah, the president’s only true confidante. Great political rivalries and their influence on the country’s affairs are also on display, as with Andrew Jackson and Whig politician Henry Clay. The book also introduces great military figures from the Mexican War, such as Gen. Winfield Scott, “Old Fuss and Feathers,— and Gen. Zachary Taylor, “Old Rough and Ready.—

It would be fitting for schools to show a map of the United States whenever discussing Polk. The idea of Manifest Destiny, “of a vast and bountiful nation stretching from the Atlantic to the Pacific,— came to fruition in his four years as president. Without him, the territorial makeup of the United States might look very different. But the chasm between Polk’s popular recognition and his accomplishments is now smaller, thanks to Merry’s work.