The most common career in the 1920s for men included farming and being servicemen on spaceships. Most of them could either farm on their own private land or get employed by others who owned land. As for the servicemen, they were used to protect by fighting any enemies.
Well at the end of the 1930's there was the great depression. 1920's and 1930's there was a lot of industrial work such as mining and building things such as cars building and such. There was also work with trains and telephones.