Final answer:
Both northerners and southerners made compelling arguments regarding the expansion of slavery after the U.S. victory over Mexico.
Step-by-step explanation:
In the context of the arguments over the expansion of slavery in the aftermath of the U.S. victory over Mexico, both northerners and southerners made compelling cases.
The northerners argued against the expansion of slavery, claiming that it was a violation of human rights and went against the principles of freedom and equality.
On the other hand, southerners argued for the expansion of slavery, emphasizing their economic dependence on slavery and the protection of property rights.
Overall, it is difficult to determine which side had a more compelling case as both arguments were significant for their respective regions. The debate over the expansion of slavery was one of the key factors leading to the American Civil War.