I thought about Alaska, but as soon as the states started fighting each other Russia would probably invade and annex it.
Hawaii wouldn't lose but I don't think it would win either, it would probably just get bored and say you know what we'll just sit this one out you guys have at it.
As for the southern states they would do well at first until all the Mexicans realized there was no point in being in America anymore and they would all go back to Mexico where it was safe taking 90% of the population of the southern half of the United states with them.
I'd imagine something similar would happen in the states bordering Canada, a lot of people would immigrate illegally to Canada to get away from the massive Civil War, leaving many of those states just ripe for the picking of Quebec who I'd imagine would succeed from Canada just to get possession of more land and actually try and create a New-France.
Most of the Mid-Western states would probably get bored trying to fight each other having to travel so far just to find someone to shoot, but not give up leading to a bunch of wandering nomadic armies all over the place out there. Even if someone actually won, they wouldn't get the message for another 30 years or so.
The South East would do pretty well until Hurricane season until it had to fight a two sided war against mother nature...
The North East would rip itself apart with so many states jam packed into such a small area, it'd be interesting to see but I don't think anyone would truly win, though I'd say New York, and Pennsylvania would probably come out the best just given numbers and how many people own guns there.
Though neither of those would be my pick of a winner, that would be Maine, because everyone would forget about them, they would just sit of there until the fighting was over then just come down riding there moose and pick off the remainders.
Then Europe would come over and steal all the useful stuff and reclaim us just like they did in the 1500's or so, cause we all know excluding Quebec, Canada really wants nothing to do with the U.S. even if it was just free land.