"The great crisis facing the country was the rebellion and anybody in the North who wanted to preserve the Union now found the principal enemy to be those Southern slave owners who had broken up the country. The institution which sustained them and the institution they went to war to defend was slavery. And more and more northerners became convinced of that. As a consequence, a lot of them went the whole way over, from being conservative, pro-Southern, pro-slavery Democrats to becoming radical Republicans. Benjamin Butler is a good example, and Edwin M. Stanton is another one."