By Allen Guelzo, Princeton University
In the August of 1846, political agendas took shape for dealing with the Mexican Cession, the territory in the far West surrendered, or ceded, by Mexico in the Treaty of Guadalupe Hidalgo. James Knox Polk proposed an Appropriation Bill which met with many oppositions.
The Wilmot Proviso
It was on August 8, 1846, when President Polk—admitting publicly for the first time that a cession of territory by Mexico was a possible result of the war—asked the House of Representatives to approve $2 million in negotiating funds.
A first-term Democratic representative from Pennsylvania named David Wilmot rose to move an amendment to the Appropriations Bill, which added to it a deadly proviso that, as an express and fundamental condition to the acquisition of any territory from the Republic of Mexico, “neither slavery nor involuntary servitude shall ever exist in any point of said territory except for crime.”
The Wilmot Proviso, as it was known, was essentially a paraphrase of the Northwest Ordinance of 1787, whose ban against slavery Wilmot wanted to be applied to the southwestern territories of the Mexican Cession. Even more dramatic, the proviso contained a frank assertion that Congress—based on Article III, Section 3, of the Constitution—had the authority to make judgments about the future of the territories.
Missouri Compromise Extension
Just as in 1820 with the Tallmadge Amendment, Congress immediately broke up along sectional rather than party lines. The northern Whigs and all but four northern Democrats in the House overrode southern votes in the House, and sent the Appropriations Bill with its lethal proviso to the Senate, but there Polk and the southern Democrats killed it.
President Polk was particularly mortified at the Wilmot Proviso, because the blow had come from a member of his own party. The administration had its own plan ready to launch, though, and they wanted to extend the Missouri Compromise line all the way through the Mexican Cession.
The idea had behind it the indisputable fact that the Missouri Compromise, with that dividing line at 36°30’, had worked for 26 years in keeping the slavery issue from polarizing Congress, and so extending it offered what looked like a solution that everybody had already agreed to earlier. What was most important of all was that President Polk was prepared to swing all the weight of his office behind it.
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John C. Calhoun’s Stance
Polk, however, now encountered resistance from his fellow southerners. On February 19, 1847, John C. Calhoun, rose to offer a set of resolutions that argued that the territories of the United States “belonged to the several states composing this Union and are held by them as their joint and common property”.
What Calhoun meant by this was that citizens of any one of the United States had equal title to the territories owned by the United States, and therefore, ought to be able to take any of their property into any of the territories, that property, of course, including slaves.
Calhoun’s Rise
Hence, not only did Congress have no authority to enact the Wilmot Proviso—which banned the transportation of slave property by southerners to the territories—but, by implication, Congress had no authority in 1820 to enact the Missouri Compromise, which banned the transportation of slaves to some of the territories.
With this one gesture, Calhoun swung the door of every federal territory open to slavery, and he swung delighted southern Whigs and Democrats behind him as the South’s great political figurehead.
Solution Offered by Lewis Cass
Northern Democrats, however, were less than enthralled with Calhoun’s logic. In December 1847, one of Polk’s chief rivals within the Democratic Party, Michigan Senator Lewis Cass, brought forward yet another option for the problem of the Mexican Cession territories.
Cass agreed with Calhoun that Congress had no authority to impose a settlement of the slavery issue on any of the territories, but that “Surely,” observed Cass, “the people who were actually living in each of the territories had the right to adopt a slave or free settlement for themselves, so let the popular will be sovereign in the territories, and let popular sovereignty defuse the confrontations in Washington over slavery, and free Congress from the responsibility of solving the problem.”
Cass’s proposal appealed to that fundamental American instinct that an independent and republican people had the right to make their own political decisions on their own ground. Cass’s proposition might also have taken him further along the road to the presidency, if he had not already managed to make a host of enemies within the Democratic Party.
Fate of the Missouri Compromise Extension
As it was, an unpersuaded President Polk attempted to ram his Missouri Compromise extension solution through Congress during the summer of 1848, and came out at the end of the session with nothing more to show for his efforts than a single bill authorizing the organization of the Oregon Territory without slavery.
Chronically ill and disappointed at the defections from Democratic unity by Calhoun, Wilmot, and Cass, Polk announced that he would not seek a second term as president in 1848. The Missouri Compromise extension proposal fizzled, but the worst for the Democrats was yet to come.
Common Questions about the Wilmot Proviso and the Missouri Compromise Extension
The Wilmot Proviso, essentially a paraphrase of the Northwest Ordinance of 1787, was proposed by David Wilmot to move an amendment to the Appropriations Bill. He added to it a deadly proviso that, as an express and fundamental condition to the acquisition of any territory from the Republic of Mexico, “neither slavery nor involuntary servitude shall ever exist in any point of said territory except for crime.”
Polk wanted to wanted to extend the Missouri Compromise line all the way through the Mexican Cession. The idea had behind it the indisputable fact that the Missouri Compromise, with that dividing line at 36°30’, had worked for 26 years in keeping the slavery issue from polarizing Congress, and so extending it offered what looked like a solution that everybody had already agreed to earlier.
President Polk attempted to ram his Missouri Compromise extension solution through Congress during the summer of 1848, and came out at the end of the session with nothing more to show for his efforts than a single bill authorizing the organization of the Oregon Territory without slavery.
