sentences:  Sectional tensions over the issue of the westward expansion of slavery, previously resolved by the Missouri Compromise, were reawakened with the debate over Texas Annexation and the Mexican War.Texas Annexation was the major issue in the national elections of 1844, but, despite some signs of a sectional split, the election was resolved along the established party lines.Opposition to the Mexican War and, especially, opposition to acquiring new territory, also split largely along party lines.