Did you guess Superman? Or perhaps Dick Tracy? Or even Tarzan? Even though these comic strip characters have been read for many years, the most popular strip today is Peanuts. The adventures of Charlie Brown, Snoopy, and Lucy are read by more people today than any other comic strip characters in history.
The record for the longest-running comic strip is held by “The Katzenjammer Kids.” The adventures of Hans and Fritz first appeared in the New York Journal on December 12, 1897, and is still running in many newspapers and comic books today, over eighty years later!
Longest running does not mean most popular, it only means that the original artists work was so easily copied and the humor so one-dimensional and middle-of-the road that countless unknowns were able to continue the strip with no noticeable decrease in quality.
The most popular strips died when either their author/artist died or decided to retire. Easliy the most popular strips in terms of readership and/or influence on the public were POGO and Calvin and Hobbs.
Long live Charlie Brown, Lucy and Snoopy!