Less like 1861 than like 1776, I think. The feds, some law enforcement some military and some politicians playing the role of the King's oppressors. Some libs playing the part of the Tory informers, very few volunteering for armed service for the regime, others hiding and trying to stay out of the line of fire. As for our side, no George Washington, but a bunch of quality lower level leaders. A lot of us holed up in a defensive posture and setting occasional ambushes; a few of us actively hunting the enemy leadership.
I agree with your take; not a pleasant thought or a cause for celebration.
However, I'm thinking of the, erm, "urban opportunists". I'd think that, in either of our scenarios, the rioting on a national scale would make the Rodney King Riots look like a Sunday School picnic. And social breakdown, particularly in the urban areas, would quickly follow. Rural areas, not so much. And suburbs would likely be somewhere in between, depending on their makeup.
That's just my $0.02.