Jeans & Dungarees
Denim workwear was as ubiquitous in the US military as it was in civilians. Much of the denim in these pants was '818' or Jelt from Cone Mills. They also produced Levi's denim at the time - probably the reason for the Navy's connection to Levi's. Cohn was subsequently awarded the Army and Navy E Award for her efforts towards the war effort.
On June 11, 1919, blue denim workwear was adopted as standard by the United States Army, replacing the brown workwear previously in use. In 1933, one-piece work suits (coveralls) were adopted in blue denim for use in similar roles by mechanics, drivers, machinists, and others. Denim has been manufactured for military purposes since the late 19th century, and the military saw no need to update the technology as it is a durable and comfortable fabric.
After the war, the evolution of denim went in a different direction. With rock and roll music and the arrival of the world's first "teenager" this time around, denim has become fashion, not workwear, and means rebellion and blue-collar coolness for the next 50 years.