Airplane factories in the United States produced some 300,000 aircraft of all types during World War II. Before the war, most factory work was done by men. As men left factories to serve in the war women took their places. "Rosie the Riveter" was born on the aircraft assembly line, as wives, mothers, and sisters started new jobs.
Factoid: A quarter of a million rivets were required to build just one bomber during World War II.