Because If I am correct, they were the first Southern State to Secede from the Union. Also, that is where the first shots of the civil war were fired.
Answer:
They ensured a huge free-state like California while giving the regions a chance to decide in favor of themselves.
They trusted the regions would cast a ballot to permit subjugation.
They trusted that if the regions cast a ballot to permit subjugation they would hold an enormous populace and various states the regions made up more land than California.
