One Rhetorical Device used was Allusion by saying, "On this hallowed ground, heroic deeds were performed and eloquent words were spoken a century ago." He was referring to:
Lincoln's "Gettysburg Address"
His tone had heavy emphases and long pauses, that helped to <span> enhance </span> the seriousness of his topic. Slow and steady with longer pauses.
Example: We do not answer him-we do not answer those who lie beneath this soil-when we reply to the Negro by asking, "Patience."