I see people talking about "survival " situations all the time and find it laughable to hear them talk of living off the land. The natural carrying capacity of America would come no where close to the population we now have. Modern agriculture has greatly increased the carrying capacity beyond what the native plants and animals could ever sustain. Reading the journal of Louis and Clark, they talk of the indians in the mountains that were near starving, the plains Indians jealously protected their food source from the others and fought to keep it.
Having and protecting a good food source would be number one in a survival situation. Dried beans and rice would be probalby the most impotant staple you could have. If a great failure of civilization were to befall us, the livestock would be first to go, then thegame animals, then pets, then vermin, then people would start eating each other. I would be willing to bet better than 90% of Americans could not preserve their own fruits vegitables and meat. Without a way to preserve good, there will be a huge amount of waste, that will make foodstocks dwindle in a very sort time.
If a situation were to come where civilization breaks down, hopefully you can find a group of people to band together with. Finding and defending a territory that will support you would be key.