Perhaps someone wonders what people were and are wearing underneath her overalls. I found by coincidence first one book and searched later for overalls and underwear. I had read before, that at least during hot summer they were wearing nothing underneath.
In the book "Ben Rod Jordan of Putnam County" which is autobiographic of the 1930s, at page 182 stands that boys (and probably men) got no underwear for spring and summer, and long underpants in winter which the parents ordered by catalogue.
In book "A nickel's worth of skim milk: a boy's view of the Great Depression" stands that there were different underwear for winter, summer and fall+spring (Page 74). But I think this was in 1938 and probably in a bigger town. Also described clothes changing for gym where all boys wearing short underpants also in winter.
In some films like "Some Things That Stay" (see that entry) I can't seeing underwear while Kevin Zegers undressing for skinny dipping.
In "The Waltons" Jim-Bob and Ben wearing short underpants underneath and swimming in them (but late 1930s). And swimming in bathing costumes in season 1 (early 1930s, I think.) I know of bathing costumes in much earlier times and assume, they don't want to show nudity. Might also be sinful to swim naked (except for boys only).
I wonder what girls wearing underneath, but bibs were mainly worn by boys and men.
Another interesting thing in book "Always of Home: A southern Illinois Childhood" it's described that the schoolhouse
smelled of new overalls and starched dresses the first week until the next wash day.
Lucky teachers.
Most parts of the books can be viewed at Google Books.
