Lincoln didn't want slavery to extend into the new territories. That alone was enough for the slave holders in the south to plan to assassinate Lincoln on his way to Washington and when that failed, for them to try and leave the union. To placate them Lincoln even was willing to go so far as to support the Corwin amendment, but that wasn't enough for them - they wanted slavery to expand.
https://en.wikipedia.org/wiki/Corwin_Amendment
>...the poor white trash type
You probably didn't intend it, but this really feels like an ethnic slur.