"This is my great grandma and her sister in their first bathing suits. She told me they were so embarrassed because the bathing suits were so skimpy! Still a teenager, this picture would have been taken no later than 1925."
The full image is the first photo I posted. Most of these beauties are from Shorpy, a very wonderful photo archive site. You can find the large, high-quality version with a bit more information here. I’ve had a lot of these images saved on my computer so unfortunately I don’t have original links for most of them.