When he was elected President in 1845, James K. Polk was only 49 years old-at that time the youngest president ever to be elected. He faced a conflicted nation on the verge of tremendous territorial expansion. James K. Polk's four years in office marked the greatest period of territorial acquisition in the history of the country-what New York journalist John O'Sullivan termed as the 'Manifest Destiny' of the United States to expand across the continent. By the end of Polk's presidency in 1849, U.S. possessions included the California, Oregon, and New Mexico territories. In addition, Texas had become part of the Union. This book analyzes Polk's political career and his role in each of these territorial expansions. James K. Polk: A Clear and Unquestionable Destiny shows that they were far more complex than the moral crusade that had been labeled 'Manifest Destiny.' Southern planters wanted to protect their 'peculiar institution' of slavery by adding new territories from which slave states would be carved. Commercial interests feared that war with England over any of these territories would adversely impact upon the nation's trade. Although the Oregon boundary dispute was settled with little friction, the Mexican War erupted after the annexation of Texas. This fascinating biography of our eleventh president and his successful efforts for expansion of U.S. territory will be of interest to students studying United States history, foreign policy, and the massive territorial expansion in the 1840s known as Manifest Destiny.