1) He gives yet another thwack on the head to anyone who still thinks that the north should have done more to avoid the Civil War or that slavery should have been allowed to take its natural course and die out on its own. Yes, Lincoln tried to avoid the war and yes, he was forced into it. But that doesn't mean it wasn't worth fighting, for people like the family of Jarm Logue.
2) That history books desperately need revising, if for no other reason (and there are many) than to give a balancing view of Daniel Webster, that great orator:
WHEREAS, Daniel Webster, That base and infamous enemy of the human race, did in a speech of which he delivered himself, in Syracuse last Spring, exultingly and insultingly predict that fugitive slaves would yet be taken away from Syracuse and even from anti-slavery conventions in Syracuse, and whereas the attempt to fulfill this prediction was delayed until the first day of October, 1851, when the Liberty [anti-slavery] party of the State of New York were holding their annual convention in Syracuse; and whereas the attempt was defeated by the mighty uprising of 2,500 brave men, before whom the half-dozen kidnappers were 'as tow', therefore,3) To loosely paraphrase Monsieur Goldwater, that moderateness in the face of dangerous extremism is no virtue.
Resolved, That we rejoice that the City of Syracuse- the anti-slavery city of Syracuse- the city of anti-slavery conventions, our beloved and glorious city of Syracuse- still remains undisgraced by the fulfillment of the satanic prediction of the satanic Daniel Webster.
There's also a corollary to lesson 3 -- a reminder of what real dangerous extremism looks like. It looks like an aging woman, ordinary in every respect, writing a freed man to remind him that she owns him and telling him to make recompense so she won't have to sell him.