Answer:
The United States' militant westward expansion in the 19th century profound affected American Indians and contributed to tensions over slavery.
Explanation:
Rooted in the idea of manifest destiny, the United States militantly expanded westward across the continent in the 19th century.
Americans saw their nation’s mission as one of bringing education, modern technology, and civilization to the West and driving away the “uncivilized” American Indians.
In the mid-19th century, the quest for control of the West led to the annexation of Texas and the Mexican–American War.
Efforts to seize western territories from native peoples and expand the republic by warring with Mexico succeeded beyond expectations; few nations had ever expanded so quickly.
This expansion led to debates about the fate of slavery in the West, increasing tensions between the North and South that ultimately led to the collapse of American democracy and a brutal civil
