1900-1985. Lots of info about the creator of Dick Tracy at http://www.chestergould.org . According to Jim Johnson of the Museum, "Peppy" was one of the 60 (!) strips created by Gould between 1921 and 1931, all prior to the introduction of Dick Tracy. The strip below is pictured in Garyn Roberts's book "Dick Tracy and American Culture."
If anyone has additional information about his "Peppy" strip, please let me know!