Mexican War Of 1846-1848

Additional territories gained from the U.S.–Mexican War of 1846–1848 heightened the slavery debate. Abolitionists fought to have slavery declared illegal in those territories, as the Northwest Ordinance of 1787 had done in the territory that became the states of Ohio, Indiana, Illinois, Michigan and Wisconsin. Advocates of slavery feared that if the institution were prohibited in any states carved out of the new territories the political power of slaveholding states would be diminished, possibly to the point of slavery being outlawed everywhere within the United States. Pro- and anti-slavery groups rushed to populate the new