Western Expansion, Manifest Destiny, and the Mexican-American War

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What were the negative effects of Manifest Destiny?

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The most obvious negative effects of westward expansion, or "manifest destiny," before the Civil War were felt by Native Americans and Mexicans. Essentially, proponents of westward expansion envisioned a West controlled by white Americans. Native peoples were driven from their lands onto reservations in places, and the expansion to the Pacific began a process that eventually resulted in the near-destruction of Plains Indians. Additionally, westward expansion directly led to war with Mexico from 1846 to 1848. President James K. Polk made expansion to California the centerpiece of his campaign, and he took the nation into war to fulfill this pledge. In the peace treaty that followed the war, Mexico lost the entirety of what is today the American Southwest. "Manifest destiny" also contributed to the political crisis that culminated in Southern secession and the Civil War. As the United States gained new territories in the West, debates began over whether slavery would be allowed in them. The question of slavery was resolved in California by the Compromise of 1850, but this solution was only a temporary one, as it convinced Southerners that Northern politicians—especially the new Republican Party—were dedicated to the destruction of slavery. So, westward expansion, and the ideology of "manifest destiny" that promoted it, had profoundly negative effects for many people.

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There were some negative effects that arose from the policy of Manifest Destiny. The policy of Manifest Destiny was the desire of the American people to spread their way of living over all of the lands between the Atlantic Ocean and the Pacific Ocean. As a result of the westward movement of the American people, Native Americans suffered greatly. In the 1830s, Native Americans were forced to move to lands west of the Mississippi River. Then, when Americans moved further west, they had to give up the lands that they had received that were located west of the Mississippi River. There were many battles with the United States Army, many of which the Native Americans lost. Their way of life was destroyed, and they suffered greatly from diseases that were spread as the American people moved onto the lands of the Native Americans.

The policy of Manifest Destiny also led to a war with Mexico. The United States had long wanted to take over what is now the southwest part of the United States. However, this land was controlled by Mexico. Mexico had no intention of selling it to the United States. When the United States moved their military into the land that was in dispute, Mexicans attacked American troops. This led to the start of the Mexican-American War. While the United States won this war, the actions of the United States were largely responsible for the start of the war.

As a result of the policy of Manifest Destiny, the United States gained a great deal of land. This led to many disputes regarding whether slavery would or would not be allowed in these territories. Because compromises failed to permanently resolve the issue about the spread of slavery, the United States would ultimately enter into civil war.

There were some negative consequences of the policy of Manifest Destiny.

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