The Dodge plant, Chicago Illinois, USA. World War Two.
I highly recommend without reservation or qualification this You Tube video. A must.
The super factory manufacturing the super engine for the super bomber. The latter the B-29 Superfortress.
The Dodge plant built entirely from scratch, at the time the most advanced manufacturing facility in the world.
Need I say or remind any devoted reader to the blog that the B-29 Superfortress [Enola Gay] dropping the first atomic bomb on Japan. Courtesy aircraft engines the Dodge plant.
Chicago, Illinois, USA the "Second City", the labor force absolutely vital to the American war effort. Again, need I mention the Manhattan Project, experimental atomic reactors CP-1 and CP-2, etc. Chicago, the B-29 bomber, the atomic bomb, all hand in glove as they say.