In the Biographical Encyclopedia of Dauphin county of 1896, there is a write-up on page 1085 on Moses Koppenhaffer, a son of Jonathan and Catherine (Hopner) Koppenhaffer. Jonathan Koppenhaffer died in 1890, aged 88, so would have been born about 1802, presumably about the same time as your George Koppenhaffer. The parents of the above Jonathan Koppenhaffer were Michael Kippenhaffer and Catherine Garrett and they had a family of sons and daughters. Unfortunately, none of the names of the sons and daughters except for Jonathan, are given. Jonathan and his wife had 11 children named Emanuel, Angeline, Moses, Sarah, George, John, Elizabeth, Catherine, Mary Jane, Emeline, and Rebecca. Jonathan and Catherine Hopner Koppenhaffer's family was born in Mifflin township in Dauphin county. My guess is that your George is a brother of Jonathan's and therefore a son of Michael and Catherine Garrett Koppenhaffer. Hope this helps out a bit, Sue