Z

Wilmot Proviso and Texas-Mexico Compromise (Chapter 4)

The Wilmot Proviso and the Road to the Compromise of 1850

  • Background context: Two-thirds of the volunteer soldiers in the major campaigns of the Mexican War came from slave states, highlighting how sectional loyalties fed into national politics. The Wilmot Proviso emerged against this backdrop as a focal point of conflict between North and South.

  • The Wilmot Proviso (August 8, 1846):

    • Proposed by David Wilmot, a Democratic congressman from Pennsylvania, as an amendment to an appropriation bill:
    • text: "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 part of said territory."
    • Purpose: To prohibit slavery in the territory won from Mexico; it became the lodestone of sectional conflict for about fifteen years.
    • Support base: Northern Democrats formed the core of support; opposition came from Southern Democrats and their allies.

  • Grievances driving the Proviso:

    • Polk administration goals: Dismantle Whig-era federal programs for economic development; debates over tariffs and internal improvements.
    • Specific grievances among Northern Democrats:
    • Walker Tariff of 1846 reduced duties on many commodities, seen as a concession to tariff-conscious constituents in Pennsylvania.
    • Polk’s veto of a rivers-and-harbors improvements bill that would have aided Midwestern Democrats and their constituents.
    • War policy linked to Oregon and the broader expansionist agenda; friction with Van Buren factionalism in New York and New England.
    • Northern Democratic fear: Support for the war might be construed as pro-slavery expansion; leaders worried about political punishment at the polls if they appeared to back war to extend slavery.
    • Public statements reflecting tensions:
    • A New York party leader: "There have been enough northern democrats who have sacrificed themselves to southern interests and I do not wish to see any more."
    • Gideon Welles (Connecticut Democrat), July 1846: warning that the South would not yield and that northern concessions were running thin.

  • Southern counterposition and rhetoric:

    • Southern Democrats had sabotaged Van Buren in 1844, pushed the Walker Tariff, and supported the rivers-and-harbors veto; a South-leaning executive demanded maximum territorial claims (e.g., Oregon) while insisting on all of Texas.
    • Fear: If free territories expanded, slavery could be undermined; the South framed the Proviso as a direct challenge to their property rights and honor.
    • Threats of disunion and drastic measures were oft-repeated in response to the Proviso.

  • Calhoun’s constitutional defense (the Southern position):

    • February 19, 1847: Calhoun introduced resolutions arguing the territories were the “common property” of the states; Congress had no power to deny citizens the right to take their property (slaves) into the territories.
    • If slavery were entirely excluded from the territories, the balance of slave and free states would be upset and the South warned of losing political power.
    • Private letter to a friend (same day): warning that if the South flinched, the Union could be dissolved; standing fast would force the North to yield or push toward independence.
    • Core claim: Slavery as a constitutional right would remain legal in all territories; exclusion would undermine the South’s political leverage.

  • Compromise attempts and proposals between Wilmot and Calhoun:

    • Missouri Compromise line extension (36°30′): a proposed compromise to extend the line to the Pacific; territories north of the line would be free, south of the line could allow slavery.
    • Details of the proposed 36°30′ extension (as seen in this text):
    • Oregon territory, Utah, Nevada, western Colorado, and the northern half of California would be organized without slavery.
    • Oklahoma, New Mexico, Arizona, and southern California would be organized with no restrictions against slavery.
    • Popular sovereignty (the Cass proposal):
    • Proposed by Michigan Democrat Lewis Cass, late 1847: leave to the people of the territory the decision about slavery for themselves.
    • Ambiguity: questions persisted about when the people would decide (territory vs. statehood) and how this would be applied.
    • Northern Democrats generally understood sovereignty to mean territorial decision-making, while Southern Democrats understood it as state-level control over property in slaves.
    • The political effect: Despite disagreements, most Northern and Southern Democrats endorsed popular sovereignty in principle, preserving ambiguity for the 1848 presidential campaign.

  • The Election of 1848: sectional splits and party dynamics

    • Democratic Party split emerged over the slavery issue at the national convention:
    • New York delegates: Barnburners (Van Burenites) pledged to Wilmot Proviso; Hunkers (pro-South) courted compromise.
    • Barnburners rejected seating both delegations and bolted, nominating Martin Van Buren on a splinter ticket; the remaining Democrats nominated Lewis Cass with a platform that avoided strong stances on slavery.
    • James G. Birney’s presence as a potential spoiler in some regions reflected the fragility of the party’s unity.
    • Cass’s nomination reflected a coalition among moderate Democrats who favored popular sovereignty.
    • The Whig Party:
    • Nominated Zachary Taylor, a Mexican War hero who had not been politically active and who owned slaves, complicating antislavery sentiment in the party.
    • The Whigs tried to minimize sectional strife by nominating a political outsider and avoiding a detailed platform.
    • In Massachusetts, the split between Conscience Whigs (antislavery, reform-minded) and Cotton Whigs (dependent on Southern cotton interests) exposed internal tensions.
    • Additional notes on party dynamics:
    • The Barnburner split and the Cass nomination signaled a move toward deeper sectionalization of national politics.
    • The convention dynamics foreshadowed the emergence of new alignments and foreshadowed Civil War-era tensions.

  • The Mexican War’s military and territorial outcomes

    • The war was popular in most parts of the country, making it politically risky to oppose it, despite opposition among some Whigs and a minority of Northern Democrats.
    • Military success:
    • Generals Zachary Taylor and Winfield Scott led a sequence of victories against larger Mexican forces, culminating in the capture of Mexico City in September 1847.
    • Additional territorial gains included Santa Fe, New Mexico, and California’s subjugation.
    • Reasons for American military success included superior artillery, disciplined infantry, and notably, the leadership of American officers who would become Civil War leaders:
    • Robert E. Lee, Ulysses S. Grant, Thomas J. Jackson, Albert S. Johnston, Joseph E. Johnston, George B. McClellan, Pierre G. T. Beauregard, James Longstreet, Braxton Bragg, Joseph Hooker, George Gordon Meade, George H. Thomas, and Jefferson Davis.

  • Treaty of Guadalupe Hidalgo (February 1848) and territorial consequences

    • Terms of the treaty:
    • Mexico ceded all claim to Texas north of the Rio Grande.
    • Mexico ceded New Mexico and California to the United States.
    • The United States paid $15 million and assumed Mexican debts to Americans.
    • Territorial extent included present-day California, Nevada, Utah; most of Arizona and New Mexico; and parts of Oklahoma, Colorado, and Wyoming.

  • Territorial expansion and the scale of conquest

    • In the three years following the war, the United States acquired about 1.25 imes 10^6

    square miles of new territory, roughly half of which lay south of the line of 36^ rac{1}{2}30' (the Missouri Compromise line).

    • The expansion reflected a strong push by expansionists and fueled debates over the future status of slavery in new acquisitions.

  • Overview: shifts in party politics and the stage for future conflict

    • The Wilmot Proviso and subsequent battles over slavery in the territories marked a turning point in American political life.
    • The formal and informal threats of disunion by Southern leaders underscored the fragility of the Union.
    • Compromise efforts (36°30′ extension, popular sovereignty) revealed an attempt to stabilize politics through ambiguous terms, while laying groundwork for future conflicts.

  • Connections to broader themes and real-world relevance

    • The Wilmot Proviso exposed how war gains and territorial expansion could intensify sectional antagonisms within national parties.
    • The era showed how constitutional arguments (Calhoun’s “common property” theory) could be used to justify slaveholding in new territories.
    • The period foreshadowed the Civil War by showing that party alignments were becoming increasingly sectional rather than national.
    • The debates around popular sovereignty highlighted the limits of democratic principle when it collided with entrenched interests in slavery.

  • Ethical, philosophical, and practical implications

    • Ethical concerns: Was it just to expand a system of slavery into new territories? Was it the rightful interpretation of property rights to the slaveholding states?
    • Philosophical questions: What does popular sovereignty imply about the consent of territories versus states? How should federal power balance regional moral economies?
    • Practical consequences: The new political alignments would influence the 1848 and 1852 elections, turning party platforms into instruments of sectional compromise or conflict.

  • Key numerical references and terms for quick recall

    • Wilmot Proviso date and clause: August 8, 1846; clause stating that neither slavery nor involuntary servitude shall exist in any territory acquired from Mexico.
    • Territory acquired after the war: approximately 1.25 imes 10^6 square miles.
    • Treaty price: 15{,}000{,}000 dollars; debts to be assumed.
    • Geographic line for the old Missouri Compromise: 36^\circ 30'.
    • Territorial outcomes of the Guadalupe Hidalgo treaty: Texas north of the Rio Grande; NM and CA ceded; other western territories included.

  • Summary of the broader significance

    • The Wilmot Proviso catalyzed a long struggle over the expansion of slavery into new territories.
    • Calhoun’s defense and the 36°30′ compromise proposals illustrate early attempts to balance sectional interests in a growing nation.
    • Popular sovereignty introduced ambiguity that temporarily delayed a definitive national settlement but ultimately failed to prevent deeper sectional split.
    • The 1848 elections and party realignments foreshadowed the emergence of more entrenched sectional politics and the eventual path to Civil War.

  • Note on sources and cross-references in this chapter

    • Several scholarly voices are cited in this material, including Morrison, Holt, and Foner, highlighting debates on how the Wilmot Proviso and related controversies shaped party dynamics and sectionalism.