American politics in the 1820s and 1830s had been dominated by domestic issues: the banks, tariffs, and internal improvements. In the 1840s, foreign policy— “American expansion,” more accurately—took center stage. The shift was due in part to the political opportunism of John Tyler, William Henry Harrison's vice president. A former Democrat who had broken with Jackson over nullification, Tyler became president when Harrison died after just a month in office. Tyler really did not support the Whig program; his vetoing of bills that would have reestablished the Bank of the United States and raised tariffs led to the wholesale resignation of his cabinet (except Secretary of State Daniel Webster) and lost him what little support the Whig party had earlier given him.
Tyler's foreign policy. Having created so many political enemies with his domestic policy, Tyler turned to foreign affairs. The successful negotiation of the Webster‐Ashburton Treaty convinced him to call for the annexation of Texas. Secret negotiations with the Republic of Texas began in 1843, and a treaty to formalize annexation was sent to the Senate in April 1844. Tyler claimed that if the United States did not take Texas, Great Britain would. Despite his arguments, opposition to the treaty was strong from both Whigs and Democrats; many saw the annexation as a plot to scrap the Missouri Compromise and extend slavery, while others feared war with Mexico. The treaty was rejected handily.
Defeat was not the end of the matter, however. The election of Democrat James Polk in November 1844 on an expansionist platform suggested that the public mood had changed. Rather than quickly reintroduce the treaty, which had to be ratified by two thirds of the Senate, Tyler was able to accomplish annexation through a joint resolution of Congress, which required only simple majorities in both houses to pass. The joint resolution was approved and signed by Tyler as one of his last acts in office (March 1, 1845).
The election of 1844. The front runners for the presidency in 1844 were Henry Clay for the Whigs and Martin Van Buren for the Democrats. Before the parties' nominating conventions, the two men met and agreed to keep the issues of expansion and slavery out of the campaign. Both men published lengthy letters in the national press opposing the immediate annexation of Texas. Clay easily won the Whig nomination, but the Democrats deadlocked because Van Buren's stand on Texas cost him votes. In the end, he could not hurdle the party's rule that required a candidate to win two thirds of the vote of the convention for nomination. James Polk of Tennessee, a former Speaker of the House, was chosen on the ninth ballot. The Democratic platform called for the “reannexation” of Texas and the “reoccupation” of Oregon; in fact, one of the party's most effective slogans was “Fifty‐four Forty or Fight !,” a reference to the northernmost boundary of the Oregon Country.
Clay was on the defensive from the beginning, but he eventually came out with a qualified endorsement for the annexation of Texas. His strategy backfired. Whigs in New York had switched to the anti‐slavery Liberty party in enough numbers to cost Clay the state. Had Clay taken New York, he would have won the presidency by seven electoral votes. Only thirty‐eight thousand popular votes separated the candidates, but the margin for Polk in the Electoral College was 170 to Clay's 105.
Settling the Oregon question. Despite the rhetoric of the presidential campaign, Polk was not ready to go to war with Great Britain over Oregon. Joint occupation, however, was becoming meaningless as more and more American settlers moved into the territory. The practical reality was that Americans far outnumbered the British fur trappers, and the fur trade was in decline in any event. While the British initially rebuffed an American offer to negotiate, both countries ultimately agreed to settle their differences peacefully in 1846. The solution was to extend the Webster‐Ashburton Treaty line (the forty‐ninth parallel) to the Pacific, making some twists and turns in Puget Sound so that all of Vancouver Island went to Great Britain. That accomplished, Polk remained dissatisfied with his obtaining American control over most of the disputed part of Oregon and his bringing Texas into the Union (December 1845); he wanted New Mexico and California as well and this time was prepared to go to war, if necessary.
The rise of manifest destiny. Polk's vision of a country that stretched from the Atlantic to the Pacific was not a new idea, but soon after his election, Americans received a well‐phrased rationale to justify expansion. In 1845, John L. O'Sullivan, publisher of the Democratic Review, wrote that it was the nation's “manifest destiny to overspread and to possess the whole of the continent which Providence has given us for the development of the great experiment of liberty and federated self‐government entrusted to us.” The two words “manifest destiny” quickly caught on, soon coming to mean that those who favored expansion had God on their side and were engaged in the noble task of spreading democracy. Despite the fact that the expansionist doctrine was based partly on the notion of racial superiority—O'Sullivan referred to the “superior vigor of the Anglo‐Saxon race”—it appealed both to supporters of slavery, who wanted Texas annexed, and to antislavery advocates, who favored adding California and Oregon to the Union.
Proponents of manifest destiny claimed that a continental United States would benefit from trade with Asia, from the commercial advantages of San Francisco Bay and Puget Sound, and from lower tariffs. Sea‐to‐sea expansion would also safeguard democracy, give the nation room to grow, and preserve the essential character of the country as an agricultural nation in the Jeffersonian tradition.