Simplicissimus is a radical left-leaning magazine published in Germany from 1896 to 1944. I guess you could consider it the MAD Magazine of the early 20th century. The magazine constantly poked fun of the German military, politicians and the aristocratic elite. Many of the cartoonists that drew for the magazine were jailed for some of their controversial depictions, and the magazine was even accused of being “controlled by Jews” for their strong opposition against Hitler. But we’re not necessarily recommending this for its content (we don’t speak German). What’s interesting about Simplicissimus is its art, which is strikingly modernist for a paper published in the 1900s. Like most publications that came out of that era, some illustrations are racially insensitive, but from a historical perspective Simplicissimus is fascinating.
Every issue of Simplicissimus can be viewed online for free. If you’re only interested in the art, Coconino World has an entire section of their site devoted to the magazine with additional info on each cartoonist.