Final answer:
The South's victory in the Civil War would have led to prolonged slavery, an agricultural Southern economy, a complex political relationship between the two nations, and altered international perceptions of the U.S. The lack of Reconstruction-era reforms could have deepened racial and economic inequalities.
Step-by-step explanation:
If the South had won the Civil War, the U.S. would likely be very different today both socially, economically, politically, and internationally. Socially, the institution of slavery might have persisted in the South for a longer period, potentially delaying civil rights advancements. Economically, the South would have continued its reliance on an agricultural, plantation-based economy, which may have struggled to compete with the industrializing world. Politically, the existence of two separate nations on the American continent would have resulted in a complex relationship between the Union and the Confederacy, with the potential for ongoing disputes and even further conflicts.
Internationally, the division could have altered the balance of power in the Western Hemisphere, affecting foreign policies and alliances. Without the moral victory of abolition and a united national identity formed through Reconstruction, the global perception of the United States could have been significantly less favorable. We might also see vastly different demographic patterns, as the Great Migration of African Americans to northern cities might not have occurred in the same way.
The Reconstruction era reforms such as the 13th, 14th, and 15th Amendments might never have been passed, affecting the legal structure of civil rights. Ultimately, these changes could have created a legacy of heightened regionalism, with ongoing racial and economic inequalities more deeply entrenched than in our current timeline.