| A | B |
|---|
| Tyler's refusal to carry out Whig policies | Turned antislavery voters to the liberty party and helped elect the expansionist Polk |
| Strong American hostility to Britain | Sparked bitter feuds over Canadian rebels, the boundaries of Maine and Oregon, and other issues |
| British support for the Texas Republic | Increased American determination to annex Texas |
| Rapidly growing American settlement in Oregon | Strengthened American claims to the Columbia River country and made Britain more willing to compromise |
| The upsurge of manifest Destiny in the 1840s | Created widespread popular support for Polk's expansionist policies on Texas, Oregon, and California |
| Clay's unsuccessful attempts to straddle the Texas issue | Split the Whig party and caused the entire cabinet except Webster to resign |
| Polk's frustration at Mexico's refusal to sell California | Helped lead to a controversial confrontation with Mexico along the Texas border |
| The overwhelming American military victory over Mexico | Enabled the United States to take vast territories in the Treaty of Guadalupe Hidalgo |
| The rapid Senate ratification of the Treaty of Guadalupe Hidalgo | Thwarted the movement that advocated the United States' annexing all of Mexico |
| The Wilmot Proviso | Heated up the slavery controversy between North and South |
