Assuming worst-case scenario in the USA, what investments are safest?

Things aren't looking very good for the USA right now, and since they have the largest economy in the world, that's bad news. If the USA takes a turn for the worst and descends into a civil war, where would be the best place to have investments?

I'm thinking gold or silver, they're long time tried and true assets and I doubt they'll be going away any time soon, however, I figure it'd be a good idea to ask what all of you think.