The Southern militants contended that all Americans had equal rights in the new territories, including the right to move their slaves into them.
The issue that started the tensions between the North and South, was the issue of the expanding of slavery.
So while it would be correct to say that Harriet Beecher Stowe and her novel caused the Civil War, her writing also delivered the political impact she intended.
The Kansas and Nebraska Act of 1854 may have been the single most significant event leading to the Civil War.
The argument over slavery, the election of Abraham Lincoln, The Abolitionist Movement, and the Missouri Compromise are all leading factors that contributed to the commencement of the Civil War.
Slavery is more commonly known as the the main reason why the Civil War was declared.