If you have a coal seam near you, you may have native sulfur available. I'm not familiar with the coal seams in Illinois, but the coal on the East coast is high in sulfur and while the coal in Wyoming and Utah is much lower in sulfur. Sulfur is necessary for producing gunpowder (along with hardwood charcoal and potassium nitrate which are both easy to make at home). On the list of books to own, a good book on the local geology should be on the list since it can tell you what types of mineralogical raw materials are readily available. Knowledge of the local geology will also help you understand your risk for floods and other disasters and the soil you have for growing crops along with much more practical knowledge.