Before penicillin, a simple scratch that became infected could be deadly. As we know, penicillin was discovered by Alexander Fleming in 1928. He was a microbiologist in London who happened upon the mold and its curing properties.
He actually dropped his research on it in 1935 after writing a paper on penicillin and doing a few tests with it. A biochemist, Ernst B. Chain, read the paper and brought it to a friend to pursue further tests. Great Britain wasn’t interested in developing penicillin into a drug, though.
So, Chain and his associate brought their pitch to the US in 1939. The US was really interested in penicillin with World War II happening, because previously soldiers had died more from infections than war itself. Before 1944, penicillin was extremely precious and scarce, though. There was so little of it produced that it was extracted from the urine of patients to be reused.