After completing this chapter, you should be able to:
- Trace the expansion processes that completed the continental United States.
- Explain the underlying causes of the expansion of the United States.
- Describe the legacies of expansion.
The expansionist movement in the United States gained tremendous momentum in the 1840s. The movement, coined “manifest destiny” in the mid-1840s, justified expansion with a sense of mission and purpose, viewing American expansion as inevitable, just, and divinely foreordained. This expansion led to the addition of Texas and Oregon to the Union and was an underlying cause of war with Mexico, which resulted in the acquisition of vast territories in the Southwest, including the prize of California.
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. 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.