<P> A general lawlessness prevailed in the vast Texas frontier, and Mexico's civic laws went largely unenforced among the Anglo - American settlers . In particular, the prohibitions against slavery and forced labor were ignored . The requirement that all settlers be Catholic or convert to Catholicism was also subverted . Mexican authorities, perceiving that they were losing control over Texas and alarmed by the unsuccessful Fredonian Rebellion of 1826, abandoned the policy of benign rule . New restrictions were imposed in 1829--1830, outlawing slavery throughout the nation and terminating further American immigration to Texas . Military occupation followed, sparking local uprisings and a civil war . Texas conventions in 1832 and 1833 submitted petitions for redress of grievances to overturn the restrictions, with limited success . In 1835, an army under Mexican President Santa Anna entered its territory of Texas and abolished self - government . Texans responded by declaring their independence from Mexico on March 2, 1836 . On April 20--21, rebel forces under Texas General Sam Houston defeated the Mexican army at the Battle of San Jacinto . In June 1836, Santa Anna agreed to Texas independence, but the Mexican government refused to honor Santa Anna's pledge . Texans, now de facto independent, recognized that their security and prosperity could never be achieved while Mexico denied the legitimacy of their revolution . </P> <P> In the years following independence, the migration of white settlers and importation of black slave labor into the vast republic was deterred by Texas's unresolved international status and the threat of renewed warfare with Mexico . American citizens who considered migrating to the new republic perceived that "life and property were safer within the United States" than in an independent Texas . The situation led to labor shortages, reduced tax revenue, large national debts and a diminished Texas militia . </P> <P> The Anglo - American immigrants residing in newly - independent Texas overwhelmingly desired immediate annexation by the United States . But, despite his strong support for Texas independence from Mexico, then - President Andrew Jackson delayed recognizing the new republic until the last day of his presidency to avoid raising the issue during the 1836 general election . Jackson's political caution was informed by northern concerns that Texas could potentially form several new slave states and undermine the North - South balance in Congress . </P> <P> Jackson's successor, President Martin Van Buren, viewed Texas annexation as an immense political liability that would empower the anti-slavery northern Whig opposition--especially if annexation provoked a war with Mexico . Presented with a formal annexation proposal from Texas minister Memucan Hunt, Jr. in August 1837, Van Buren summarily rejected it . Annexation resolutions presented separately in each house of Congress were either soundly defeated or tabled through filibuster . After the election of 1838, new Texas president Mirabeau B. Lamar withdrew his republic's offer of annexation due to these failures . Texans were at an annexation impasse when John Tyler entered the White House in 1841 . </P>

Why did northerners oppose the annexation of texas