Answer:
last 2 points are, 1st point:
The philosophy drove 18th-century U.S. territorial expansion and was used to justify the forced removal of Native Americans and other groups from their homes. The rapid expansion of the United States intensified the issue of slavery as new states were added to the Union, leading to the outbreak of the Civil War
2 point: The negative effect that this had on Native Americans were lasting effects. Manifest Destiny also caused war and tension with Mexico for the same reasons. Manifest Destiny caused americans to feel entitled, greedy, power hungry, they wanted to be the best, which are poor qualities to have.
i dont know the first point sorry. hope this helps