Final answer:
Manifest Destiny justified Americans' right to expand, but the acquisition of new territories had consequences, including tensions with Mexico, displacement of Hispanics, hostilities with Native Americans, and a debate over slavery.
Step-by-step explanation:
Manifest Destiny justified in Americans' minds their right and duty to govern any other groups they encountered during their expansion, as well as absolved them of any questionable tactics they employed in the process.
However, expansion came at a price. The Mexican-American War further incited resentment of the United States by not only Mexico but also the region of Latin America. In the aftermath of the war, tensions grew between the American and Mexican populations of Texas and California as Hispanics were pushed further and further out of the dominant society, dispossessed of their land, and politically disenfranchised in the new states of Texas and California. The westward expansion also led to increasing hostilities between the United States and Native Americans, resulting in a series of disturbances, massacres, and wars. Finally, the expansionist movement further ignited the debate over slavery in the wake of the Missouri Compromise.