Hardtack is a sort of cracker/bread/jawbreaker. They used to eat it all the time in the civil war. In fact there is still some from the civil war in a museum in minneapolis that is still edible. My wife and i made some the other day and the stuff is not half bad. You just have to soak it awhile in tea or something to soften it up. Flour, water, and 2teaspoons of salt. mix flour water and salt till it is like bread dough that is hard. roll out to 1/2 inch thick cut into squares about 4x4 and poke holes all over with a toothpick. bake at 350 for 25min flip over and bake for another 25 min or so. should come out hard as a rock and last a long time. just another long term food idea.