The issue of Texas annexation had been assiduously avoided by the leading politicians of all parties ever since the Texans had succeeded in establishing their independence from Mexico in 1836. They feared that talk of annexation would immediately raise the question of adding greatly to the slaveholding area of the United States, arouse northern foes of slavery extension, and threaten to disrupt existing party alignments. Recognizing the danger posed by the slavery issue to the maintenance of the Union, President Jackson had waited until his last day in office before extending recognition to the new republic. His successor, Martin Van Buren, had abruptly declined Texas' offer to accept annexation. In the campaign of 1840, there was no mention of Texas.
Tyler, a president without a party, was free from the constraints that inhibited such leaders as Clay or Van Buren. He was not concerned about the divisive effect of Texas annexation on the Whig or Democratic party. On the contrary, he saw the possibility that by successfully exploiting the annexation issue he might form a new party supportive of his ambitions for a second term. Moreover, he was in principle an expansionist and saw in annexation an achievement that would add luster to his presidency. He contemplated acquiring Texas after the completion of the Webster-Ashburton negotiation, but Webster, who remained as secretary of state, was hostile to the idea. When Webster finally resigned in May 1843, Tyler replaced him with Abel P. Upshur of Virginia, who shared the president's ardor for annexation.
There were formidable obstacles to be overcome. Mexico had never recognized the independence of Texas and gave notice that annexation would be regarded as an act of war. Great Britain, with support from France, wanted an independent Texas, preferably with slavery abolished there, and was offering alluring inducements to the Texas authorities. Not the least of the obstacles was the likelihood that the Senate would not welcome annexation, because of the threat that it would pose to the unity of both parties. As early as March 1843, when there were rumors of Tyler's intentions, John Quincy Adams headed a group of northern congressmen who published an "Address to the People of the Free States," warning against a "slaveholders' plot" to extend the bounds of slavery. On the other side, a small number of southern Democratic politicians were scheming to use the Texas issue to deprive Van Buren of the party's nomination in 1844.
Despite the dubious, even threatening, omens, Tyler determined to proceed. He would downplay the slavery issue and emphasize instead the economic advantages that would accrue from annexation. Even more, he would depict the British in the role of the villains, working to frustrate American expansion, posing a threat to the "domestic institutions" of the South, and securing the material advantages of an independent Texas subservient to John Bull. By late 1843, Upshur was in secret negotiation with Texas emissaries, even assuring them that the Senate would be agreeable and that the United. States would extend its protection to Texas, pending ratification of a treaty.
On 28 February 1844, matters took an unexpected turn. President Tyler, members of his cabinet, other Washington dignitaries, and their guests accepted an invitation from Captain Robert F. Stockton to take a cruise on the Potomac on the Princeton , the most modern ship in the navy. On the homeward trip, the vessel's huge naval gun, the "Peacemaker," was fired for the entertainment of the company. It exploded, with catastrophic effect. Total casualties were eight dead, including Upshur and Secretary of the Navy Thomas W. Gilmer, and eleven injured. With inadequate forethought, Tyler chose John C. Calhoun as Upshur's replacement. A southern extremist, whose most recent candidacy for the presidency had been abandoned in failure a few months earlier, Calhoun was, like Tyler, a man without a party. He, too, was prepared to exploit the Texas issue, in his case by relating it explicitly to the defense of slavery.
Under Calhoun's direction, a treaty of annexation was signed on 12 April, and ten days later it was sent to the Senate. In his message urging approval, Tyler began with the dubious assertion that Texas had been acquired as part of the Louisiana Purchase in 1803, ignoring the fact that if such a claim had any basis, it had been renounced by the Adams-Onís Treaty in 1819. More cogently, he argued the economic benefits to be gained by "reannexation." But his strongest plea was that if the United States did not take Texas, it would "force Texas to seek refuge in the arms of some other power," a thinly veiled reference to Britain.
A few days later he forwarded to the Senate correspondence between Calhoun and Richard Pakenham, the British minister in Washington. In his letter to Pakenham, Calhoun went to extraordinary lengths to tie annexation to a justification of slavery, holding forth on the dire consequences to the South if Britain should be successful in securing the abolition of slavery in Texas. To oppose annexation, as Calhoun defined the issue, was to place slavery in the United States in jeopardy. In mid-May, Tyler continued his campaign for ratification by sending the Senate a letter from Andrew Jackson that argued that if annexation were not accomplished promptly, "Texas might from necessity be thrown into the arms of England and be forever lost to the United States." In South Carolina, an effort was launched to hold a southern convention to rally that region behind annexation.
The treaty met with a negative reception in the Senate. Northern senators denounced it as an overt invitation to war with Mexico and as a slaveholders' plot led by a desperate and repudiated president. Some professed to see it as having been contrived solely for political ends—to deny Van Buren the presidential nomination and to advance the candidacy of Tyler. Almost without exception, the Whigs, regardless of section, opposed the treaty and castigated Tyler for raising the issue. Finally, on 8 June 1844, the treaty was brought to a vote. Only sixteen senators—fifteen Democrats and one Whig—voted affirmatively; thirty-five were opposed. Undaunted, Tyler sent the rejected treaty and relevant documents to the House of Representatives two days later, repeating his warning that Texas would throw itself into the arms of England and intimating that the House should initiate the process of annexation by joint resolution.