How did the American belief in "Manifest Destiny" contribute to the U. S.-Mexican War? X a. Many Southerners favored the institution of slavery, which was opposed by Mexico.
b. Even after the U. S. annexation of Texas, its southern border with Mexico was still disputed.
c. Many Americans wanted to seize lands belonging to Mexico in order to extend the U. S. west.
d. Most Northerners opposed the annexation of Texas as a slave state.