WWII
During WWII, St. Louis' factories transformed into war factories. St. Louis produced massive amounts of Uranium, it was of the six cities in the United States where uranium was processed. Within a week of the end of the war, twenty thousand workers were laid off. Curtiss Wright's aircraft factory, Mallinckrodt's chemical company, and Monsanto's TNT chemical weapons factory were all well known during this time. The St. Louis economy during World War II was dependent upon war factories, and within a week of the war's ending 20,000 St. Louis residents lost their jobs.