Dark Horse -   · An unexpected political candidate

Distribution Act -   · An Act sponsored by Henry Clay that sent the government's surplus tax revenue back to the states on an equalized basis. Polk objected to the bill because it actually only gave the money as a loan. Therefore, the states might be liable for repaying the money later.

Fifty-Four, Forty or Fight -   · Polk's expansionist campaign slogan, a reference to the 54th parallel, the Alaskan border. The U.S. claimed that the Oregon territory stretched all the way up through Canada.

Manifest Destiny -   · Manifest Destiny was a phrase used by politicians in the 1840s to explain and justify continental expansion by the United States all the way across to the Pacific Ocean. By giving the country a "mission"–to expand the liberties and freedom of America all the way across the country–they were able to garner support for Westward expansion, the Mexican War, and other expansionist ideas.

Monroe Doctrine -   · The Doctrine, put in place by President James Monroe which stated that European interference in the affairs of the Americas would not be tolerated.

Sub-Treasury -   · A financial tool developed by President Martin Van Buren that would place all the government's money in a government depository to prevent a crunch like the one in effect when he assumed office. The sub-treasury, though, would not be passed until Polk's administration, however, with the passing of the Independent Treasury Act of 1846.

Wilmot Proviso -   · An amendment to a bill that granted Polk the money to buy New Mexico and California from Mexico, the Wilmot Proviso prevented slavery in the new territories. The bill failed to pass because of the Proviso, thereby prolonging the Mexican War.

John Bell - Tennessee congressman and one of Polk's loudest critics and opponents. He led the effort to nominate Hugh Lawson White rather than Martin Van Buren for president.

James Buchanan - Polk's troublesome and politically ambitious secretary of state. Polk saw Buchanan as too worried about his own future to be of much help in governing. Buchanan later became president after Zachary Taylor.

Henry Clay - Missouri senator and later the crafter of the Compromise of 1850. Clay repeatedly sought the presidency on the Whig ticket and fiercely opposed Polk.

Davy Crockett - Tennessee congressman and famous frontiersman, a harsh critic of Polk's. He died at the Alamo in 1836.

Felix Grundy - Polk's mentor in Tennessee, Grundy–a former chief justice of the Kentucky supreme court–taught Polk law and later helped guide him through Tennessee politics.

William Henry Harrison -  The ninth president of the U.S. He caught pneumonia after his rainy inauguration and lived only a month in office.

R.M. Johnson - The unpopular running-mate of Martin Van Buren.

Sarah Childress Polk  - Polk's wife of a quarter century. Her cordiality won many friends in Washington for her and her husband and repeatedly she urged her husband to slow down so that he did not work himself to death. She died at age eighty-seven in August 1891 and was buried beside her husband.

Winfield Scott - The ambitious general who led the capture of Mexico City after launching an amphibious invasion at Vera Cruz. He defied repeated orders from Polk in his quest to secure the peace treaty and thus claim greater glory than Zachary Taylor. He hoped to secure the Whig nomination for president in 1848.

Zachary Taylor - The politically ambitious general who started the Mexican War and then captured much of northeastern Mexico. He succeeded Polk to the presidency in 1849.

John Tyler - The reluctant vice president for William Henry Harrison. Upon Harrison's death, he began a long switch from Whig politics to Democratic politics and eventually came to be hated by both parties. He offered Polk the position of secretary of the navy.

Martin Van Buren -  The eighth president of the U.S. and the chosen protégé of Andrew Jackson. Van Buren lost reelection in 1842 and his anti-annexation feelings cost him the nomination in 1848.