<P> The Missouri crisis of 1819--1821 sharpened commitments to expansionism among the country's slaveholding interests, when the so - called Thomas proviso established the 36 ° 30' parallel, imposing free - soil and slave - soil futures in the Louisiana Purchase lands . While a majority of southern congressmen acquiesced to the exclusion of slavery from the bulk of the Louisiana Purchase, a significant minority objected . Virginian editor Thomas Ritchie of the Richmond Enquirer predicted that with the proviso restrictions, the South would ultimately require Texas: "If we are cooped up on the north, we must have elbow room to the west ." Representative John Floyd of Virginia in 1824 accused Secretary of State Adams of conceding Texas to Spain in 1819 in the interests of Northern anti-slavery advocates, and so depriving the South of additional slave states . Then - Representative John Tyler of Virginia invoked the Jeffersonian precepts of territorial and commercial growth as a national goal to counter the rise of sectional differences over slavery . His "diffusion" theory declared that with Missouri open to slavery, the new state would encourage the transfer of underutilized slaves westward, emptying the eastern states of bondsmen and making emancipation feasible in the old South . This doctrine would be revived during the Texas annexation controversy . </P> <P> When Mexico won its independence from Spain in 1821, the United States did not contest the new republic's claims to Texas, and both presidents John Quincy Adams (1825--1829) and Andrew Jackson (1829--1837) persistently sought, through official and unofficial channels, to procure all or portions of provincial Texas from the Mexican government, without success . </P> <P> Spanish and Indigenous immigrants, primarily from North Eastern provinces of New Spain began to settle Texas in the late 17th century . The Spanish constructed chains of missions and presidios in what is today Louisiana, East Texas and South Texas . The first chain of missions was designed for the Tejas Indians, near Los Adaes . Soon thereafter, the San Antonio Missions were founded along the San Antonio River . The City of San Antonio, then known as San Fernando de Bexar, was founded in 1719 . In the early 1760s, Jose de Escandon created five settlements along the Rio Grande River, including Laredo . </P> <P> Anglo - American immigrants, primarily from the Southern United States, began emigrating to Mexican Texas in the early 1820s at the invitation of the Texas faction of the Coahuila y Texas state government, which sought to populate the sparsely inhabited lands of its northern frontier for cotton production . Colonizing empresario Stephen F. Austin managed the regional affairs of the mostly American - born population--20% of them slaves--under the terms of the generous government land grants . Mexican authorities were initially content to govern the remote province through salutary neglect, "permitting slavery under the legal fiction of' permanent indentured servitude', similar to Mexico's peonage system . </P>

How did texas eventually become the 28th state of the union