In today's excerpt - James K. Polk (1795 - 1849), the eleventh U.S. president, was one of the most aggressively expansionary presidents in U.S. history, and his actions brought vast new areas of land, including Texas, the American southwest, and the American northwest into the possession of the U.S.:

"In the fall of 1843, James K. Polk appeared to be politically dead. Despite seven terms in Congress, two of them as Speaker of the United States House of Representatives, Polk's attempt to win reelection as governor of Tennessee had failed miserably - not just once but twice. Even the political power of ex-president Andrew Jackson, now an aging sage ensconced at the Hermitage, appeared unlikely to rescue him.

"Yet eighteen months later, this man was inaugurated the eleventh president of the United States. How did this happen? Was James K. Polk really a dark horse who came out of nowhere to win the 1844 Democratic nomination, as conventional wisdom has long suggested, or was he one of the most experienced and astute politicians of his time?

"And what of the country? What forces - Manifest Destiny some called them - were at work not only to annex Texas but also in the span of four years under Polk's leadership to nearly double the American nation with the acquisitions of Oregon, California, and all of the Southwest?

"Unabashedly proclaiming the policy of the United States to be one of continental expansion, Polk welcomed Texas into the union, bluffed the British out of half of Oregon, and went to war with Mexico to grab California and the Southwest. Yet a change of just 5,000 votes in New York would have elected Henry Clay president instead. Clay appeared content to let Texas remain independent and Oregon remain in British hands. How different the map of the United States might look today if that had happened.

"Polk announced his intent to serve only one term even before his election. He immediately became a lame duck, but it allowed him to spend his political capital freely and he did so aggressively expanding the powers of the presidency more than any other president before the Civil War.

"[His story] is also the story of aging Andrew Jackson, would-be president Henry Clay, cagey Martin Van Buren, feisty Thomas Hart Benton, and a young Whig from Illinois named Abraham Lincoln, who challenged Polk to name the exact spot where American blood had been spilled as his pretense for war with Mexico. It is also the story of bruising presidential campaigns, spoiler third parties, and less than stunning popular - vote triumphs - all suggesting that recent presidential politics is nothing new.

"It has long been popular to paint James K. Polk as a dark horse, but the record does not square with that tradition. If he was indeed one, he chose to ride boldly across a bright land and in doing so opened up the American West to half a century of unbridled expansion."

Walter R. Borneman , Polk: The Man Who Transformed the Presidency and America, Random House, Copyright 2008 by Walter R. Borneman, pp. xiiv-xiv.