Was senator Charles summer for or against slavery?

Against Slavery

Explanation:

Throughout the Civil war, Charles Sumner had been the special champion of slaves, being the most vigorous advocate of emancipation, of enlisting blacks in the Union Army, and of the establishment of the Freedmen's Bureau. As one of the Radical Republican leaders in the post-war Senate, Sumner fought to provide equal civil and voting rights for the freedmen on the grounds that "consent of the governed" was a basic principle of American republicanism and in order to keep ex-Confederates from gaining political offices and undoing the North's victory in the Civil War.