airbornepoet

I was watching a documentary that said the American colonist, or UK colonist, had to import all gunpowder? They could make glass. They could have made sulfur, right? They could make charcoal I believe. I think potassium nitrate from horse urine or bat dung I saw from one source. Why could they make gunpowder instead of importing it? Could a chemist help me here? Maybe it would have taken a great effort to make enough for the whole army, but they could have had farmers from all over the place pithing in to make the ingredients.