Large public meetings have been held in various sections of the country in favor of the Union and of the Compromise measures of the last session of Congress. One was held at Philadelphia on the 21st of November, attended by six or seven thousand people, and numbering among its officers some of the most respectable citizens of Philadelphia. Hon. John Sargeant presided, and speeches were made by Messrs. Dallas, J. R. Ingersoll, Rush, Randall, and others. Letters were received from the Hon. Messrs. Clay, Webster, Cass, and other gentlemen of distinction, who were unable to be present. Mr. Randall, in his remarks, said, that the general impression, that the clause in the Constitution requiring the return of fugitive slaves was the result of a compromise, was erroneous: the records of the Convention would show that it was adopted unanimously, and without amendment. Resolutions expressive of strong attachment to the Constitution, of obligation to abide by its provisions, of determination to maintain the supremacy of the laws, of disapprobation of anti-slavery agitation, and of approval of the Compromise measures, were adopted with much applause. A very large meeting of a similar character was held at Boston, on the 26th, in Faneuil Hall. Dr. J. C. Warren, a descendant of General Warren, who fell at Bunker's Hill, presided, and on taking the chair made an eloquent and patriotic speech. Resolutions were adopted, asserting that the preservation of the Constitution and Union is the paramount duty of all classes; that the blessings flowing from the Constitution vastly transcend in importance all other political considerations; that the laws of the land are equally binding on every State, and upon all citizens, and no one can refuse, or seem to refuse to obey them; that the measures of compromise passed by the last Congress ought to be carried out by the people; that resistance to law is mischievous, and that all who advise those who may be the subject of any law, to resist, deserve the opprobrium of the community, and the severe penalty of the law; that at all times, and in all places, the citizens of Boston will sustain the Union, uphold the Constitution, and enforce obedience to the law. Speeches were made by B. R. Curtis, Esq., Hon. B. F. Hallett, and Hon. Rufus Choate, which were received with enthusiastic applause.