The Mexican War (1846-1848) was the result of many factors, not the least of which was westward expansion. Expansionists became interested in the area above the Mexican borderlands, Texas, as well as New Mexico, California and Oregon. By 1835 there were 20, 000 settlers in Texas, many of which were plantation owners who had moved in with their slaves. Texans declared their independence in 1836 and applied for annexation, but President Jackson did not recognize their independence until 1837, just before he left office. Martin van Buren, Jackson's successor, also avoided the issue of slavery…
