The Katzenjammer Kids (AKA, the Katzies, Hans und Fritz and more) debuted in 1897 in the New York Journal owned by William Randolph Heart (b. 1863 - d. 1951.) It was created by Rudolph Dirks (b. 1877 - d. 1968) and was highly popular during its time; though those higher up in society deemed the comic strip trash and was helping lead the youth of America astray and that the end of society was nigh.
Eventually, in 1914, Dirks was lured away from the New York Journal to the New York World which was originally owned by Joseph Pulitzer (b. 1847 - d. 1911) and had just moved into his three sons' hands. The Journal attempted to sue Dirks for ownership of the characters and the comic. The subsequent ruling followed the precedent set by a handful of other comics before hand; the name of the strip stayed with the Journal while Dirks could take the characters with him to the World. Thus, The Captain and the Kids came into being.
The rival comics, using very similar formats, characters and situations, continued to battle it out until 1979 when The Captain and the Kids finally folded; making it one of the most successful "imitation" comics in history.
As for The Katzenjammer Kids? It's still being syndicated; making it the longest running syndicated comic strip in history... It's currently on its 114th year and even with the slumping newspaper industry, there still appears to be quite a bit of life left in those eternally youthful kids.