CHARLES SUMNER. HON. ELI THAYER. Mr. Sumner, yielding with reluctance to the pressure upon him, consented to speak on this occasion, solely with the desire of striking a last blow at a political heresy which stood in the way of establishing Freedom in the Territories, and of helping to save an important District of Massachusetts from being represented by one of its partisans. The speech is confined exclusively to the dogma or device of Popular Sovereignty, often called Squatter Sovereignty, in the Territories, which, after playing a conspicuous part in other sections of the country, at last found a supporter in Mr. Thayer, who gave to it certain importance, inasmuch as he had already done excellent service in organizing that Liberty-loving emigration which contributed so powerfully to the salvation of Kansas. Though local in its immediate influence, the speech completes the series of efforts by which Mr. Sumner sought to fix the power of Congress to prohibit Slavery in the Territories, which was the great issue in the Presidential election. It is, perhaps, the last speech made anywhere on this topic, which unquestionably belongs to the history of the Slavery Question in our country. At its delivery there was much enthusiasm. The large hall was crowded for an hour before the meeting. Many hundreds, some from a distance, were compelled to return home, while others thronged the aisles and passage-ways. The effect of the speech was attested at the time by the public press, and also by correspondents. Mr. Bailey, the successful candidate, wrote as follows, under date of Fitchburg, November 10, 1860. “Our District was carried on high points. Our triumph is one of principle. We were in danger at one time, and felt the need of a strong, manly blow from an authoritative source. You gave such a blow, and the result is, Mr. Thayer has a plurality in but eight of the thirty-seven towns comprising our District. “The victory is not in any sense a personal one for me. But, as a member of the Republican party, a lover of the principles of personal liberty cherished by the Fathers, and an enemy of human slavery in all forms and _everywhere_, I must thank you from a full heart for the great and timely aid you then rendered to the cause in this District. Your reward, I know, is not in these thanks, but it is a satisfaction to me to express them.” Edwin Bynner, an energetic citizen of Worcester, who took a leading part in the canvass, wrote, under date of November 10, 1860:--