Politically:
African American's and whites were greatly divided politically--not severally as the northerns and southerners however, who were very mad at one another and for many years prior to the civil war refused to "work together" for lack of a better phrase.
That's really more of a social effect. Politically I think changes were made to the US government, and several laws and acts were passed and such. I'm not certain on specifics.
The political results of the US Civil War, was the firm establishment of the Democratic Party dominating Souther elections for over 100 years.
