The orator was sustained by the full consciousness that his utterances were in harmony with the grand sweep of historic truth as well as with the spirit of the present age.
Sumner was not a party man and was at no time in complete harmony with his coworkers.

It was always a question whether his speeches had a favorable effect upon the immediate action of Congress; there can, however, be no doubt of the fact that the larger public was edified and influenced.

Copies of "The Crime against Kansas" and "The Barbarism of Slavery" were printed and circulated by the million and were eagerly read from beginning to end.

They gave final form to the thoughts and utterances of many political leaders both in America and in Europe.
More than any other man it was Charles Sumner who, with a wealth of historical learning and great skill in forensic art, put the irrepressible conflict between slavery and freedom in its proper setting in human history..