It is very much hard to answer.
It was mainly because of how the North and the South of America had different lifestyles and economy's. You would be surprised to know that the Democratic party back then supported Slavery and the republicans dint support Slavery.
Plain Answer: Because of Slavery, Way of Life and Different Economy. The Democratic Party would do anything to keep themselves supported.
During the development of an organism, from a single fertilized egg into adult form, cells become specialized through a process called differentiation.
During differentiation, genes that are activated determine the type of cell it will become. I hope that's what you need
He viewed them as vicious humans that didn't feel bad for individuals out of their race.