Final answer:
Manifest Destiny is often seen as positive for spreading democracy and uniting the United States from coast to coast, but it also had negative impacts, including the displacement of Native Americans, cultural assimilation, and the exacerbation of the slavery debate.
Step-by-step explanation:
Many Americans believed Manifest Destiny was a positive event, as it represented the fulfillment of their natural and divine right to expand and prosper across the continent. Proponents felt that the expansion helped spread the principles of democracy and American values, and played a critical role in the growth of the United States. This westward movement united the country from coast to coast, thus fulfilling the vision of a nation stretching "from sea to shining sea."
However, it cannot be overlooked that Manifest Destiny also had numerous negative consequences, particularly for the Indigenous populations and Mexicans living in the areas that were annexed. These groups were often forcibly removed from their lands, subjected to American cultural assimilation, or marginalized in the new political order. Furthermore, the expansion intensified debates over slavery, contributing to the sectional tensions that eventually led to the Civil War. Ultimately, while some believed that Manifest Destiny was a force for good and a showcase of American exceptionalism, others saw it as a justification for imperialist expansion and the cause of significant suffering.