Manifest destiny
Was a cultural belief in the 19th-century United States that White American settlers were destined to expand across North America.
There were three basic tenets to the concept:
- The inherent superiority of the American people and their institutions
- The mission of the United States to redeem and remake the West in the image of the agrarian East
- An irresistible destiny to accomplish this essential duty
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Manifest destiny ... was used by Democrats in the 1840s to justify the Mexican–American War and to negotiate the Oregon boundary dispute.
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By 1843, former U.S. President John Quincy Adams, originally a major supporter of the concept underlying manifest destiny, had changed his mind and repudiated expansionism because
it meant the expansion of slavery in Texas.