In 1902-04, the magazine Vanity Fair (unrelated to the current magazine of the same name) was a precursor to the "girly magazines" that followed. One of the raciest things they could publish was women wearing pants, meaning you could actually see that they had two legs! They were called "bifurcated girls," as if they were split in two. Bifurcated girls were a regular feature of the magazine, and in 1903 it published a special issue featuring a full set of pictures of women in men's clothing (sometimes accompanied by women in skirts, outrageously showing their petticoats). See more at the Public Domain Review. Link -via Everlasting Blort
Pshaw, I say to you sirs. Pshaw indeed!