While not a true story, All My Sons is based on a real incident. For two years during World War II, the Wright Aeronautical Corporation, a subsidiary of the Curtiss-Wright Corporation, knowingly sold aircraft engines that leaked gas to the US army, leading to the deaths of US pilots. The company was caught when frontline workers informed the government about the fraud. This was the most prominent of several scandals involving faulty materials sold to the government for the war effort: in another, US Steel sold faulty metal for warship construction, leading one ship to sink. Miller, however, based his play on the Wright Corporation incident.
In the play, the defective engines are changed to defective cylinder heads, knowingly sold by fictional characters Steve Deever and Larry Keller, both of whom put protecting their company and their own jobs ahead of the welfare of the young pilots who lost their lives as a result of the sale.
Miller fictionalizes a true story in order to make a larger comment about the American Dream. An important theme of the play is that the entire war was a waste of American lives if Americans don't learn from what happened and put more value on their fellow humans and less on materialism and profit.