Answer:
<em>The United States' militant westward expansion in the 19th century profound affected American Indians and contributed to tensions over slavery.</em>
Explanation:
<em>Rooted in the idea of manifest destiny, the United States militantly expanded westward across the continent in the 19th century.</em>
<em>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.</em>
<em>In the mid-19th century, the quest for control of the West led to the annexation of Texas and the Mexican–American War.</em>
<em>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.</em>
<em>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 </em>
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