In the 1940s, we used to make our own explosives (salt peter, sulfur and charcoal ground up together). Got the formula from the familys 11th edition of the Encyclopedia Britannica. A kid could buy potassium nitrate then at the local drugstore ... made firecrackers out of toilet-paper rolls wrapped with layers of glued string which made an impressive pop.
Now, I gather, a kid my age back then would not be able to walk up and buy gasoline.