The answer is False.
The American Civil War, which took place from 1861 to 1865, was fought over a variety of complex issues, with the primary and most contentious being the institution of slavery. While the concept of states' rights was indeed a significant factor, it was largely invoked by Southern states to defend their right to maintain and expand slavery.
This option is incorrect because it oversimplifies the causes of the Civil War. While states' rights were a part of the conflict, they were often cited in the context of preserving the institution of slavery. The Southern states seceded from the Union primarily to protect their economic and social systems, which were heavily dependent on slavery.
This option is correct. The Civil War was fought over multiple issues, including economic differences, political disputes, and, most importantly, the moral and legal status of slavery. The election of Abraham Lincoln, who was opposed to the expansion of slavery, was a significant trigger for the secession of Southern states. The war ultimately led to the abolition of slavery with the 13th Amendment to the U.S. Constitution.