The Katzenjammer Kids, or The Captain and The Kids is without a doubt the longest running American newspaper comic strip, started on December 12, 1897 and inspired in part on the grizzly illustrated German children’s rhyming story book Max and Moritz first published in 1865, it continues under news hands to this day for a total of 174 years.
Is my math off?
No, because for 61 years of their career the almost demonic Hanz und Fritz, their ever oblivious Mama, her paramour The Captain and arch enemy The Inspector, a truant officer, led parallel lives in two different strips, the original, Katzenjammer Kids, which still runs today, and The Captain and the Kids which was done by the fellow who started the first strip in 1897, and who after working on it for 15 years took a little vacation only to find himself replaced by another cartoonist / writer, but who got awarded the right to do the exact same strip as long as he called it something else, and which ran until 1979. (and you thought the Captain Marvel non-sense was crazy)
Whatever the case for 61 years they ran simultaneously just distributed by different newspaper syndicates. With the same 5 main characters, up to basically the same high jinks, at first the only differences being that in Captain and the Kids Hanz was brunette and Fritz was the blond (or was it the other way around?)
However after a time differences started to take place which there being more sustained stories in the Katzenjammer Kids with pirates and them moving to Squee-Jee Island in the tropics in 1936, and in the 50’s even dealing with alien invasions, while The Captain and the Kids stuck mainly with short gag strips featuring the brothers playing a prank on The Captain and / or Inspector, then getting a spanking, which they after a time could no longer even feel.
However the Captain and the Kids version did shake things up for about 4 years during the height of anti-German feelings during World War I when the Kids were renamed Mike & Aleck, The Shenanigan Kids, while over at the original strip it was just explained that they weren’t German… they were Dutch.
As for the characters, the two immortal brats and their odd family group, while much reduced (they only appear in around 50 papers) they still prank on to this day, and turned up (at least in name) in the recent film Inglorious Basterds.