I've posted before about what people found dirty in previous decades, as well as cartoons from the twenties, but here is a combination of both.
For some reason, Americans (U.S. ones) have always found the french dirtier than them. What was considered dirty is of course tame more than ninety years later. This was under-the-counter stuff you wouldn't want to be seen in public with, translated from foreign publications that weren't named. I don't have the exact date, but it was before Harold Ross's edict that cartoons only having one or no captions became the standard.
2 hours ago