Which view helped push the North and the South apart by 1861?

Most Southerners wanted to expand the rail network, while most Northerners did not.

Most Northerners believed in women's suffrage, while most Southerners did not.

Most Southerners supported Chinese immigration, while most Northerners opposed it.

Most Northerners opposed the expansion of slavery, while most Southerners supported it.