Abolitionists meet at Faneuil Hall, Boston to protest the arrest of Anthony Burns

"Learning of the arrest, Boston's Vigilance Committee staged a mass protest meeting in Faneuil Hall on the evening of 26 May that abolitionists Wendell Phillips and Theodore Parker addressed. At its midpoint a militant faction, headed by Thomas W. Higginson, interrupted the proceedings to lead an armed attack on the Boston Court House to rescue the prisoner. The attack was repulsed, but a guard, specially deputized into federal service, was killed. To counter any more rescue attempts, the federal officials promptly assembled a posse; it consisted of approximately 180 soldiers and marines and 120 armed civilians known as the 'marshal's guard.'"  David R. Maggines, American National Biography Online.