hard tack is not very tasty, but it keeps a long long long long time, thats why the pioneers, and civil war, and rev war soldiers ate it. It was also cheap which is another reason that the army fed it to them. basically, it is extremely easy to make, you take about a pound of flour, about a tablespoon of salt, and enough cold water to make a STIFF dough. kneed it out till everything is combine. It will be hard to kneed,a nd doesnt need to be pretty. roll it out till it is aobut a half inch thick. cut it into three inch by three inch crackers, then take a nail and poke nine holes in each cracker. heat the oven to 425 and bake until its golden brown. there is a reason they call these "crown breakers" when they are fresh, they are pretty easy to eat, but alot of reenactors let them sit and age. they are more authentic when they are stale. the Civil war soldiers often dunked them in their coffee to soften them, or they would soak them in water and then fry them in bacon grease. the easiest way to eat them is to break them up with a mallet, and gum them.
Have fun