It is likely that there are at least two and probably several unrelated Pitner lines in America. The surname of our Pitner line was probably "Buttner" or "Beatner", and the family may have been French Huguenots, who fled to Germany first, and then to America. According to family tradition from the Illinois Pitners, Adam Pitner and three sons landed in Philadelphia. Adam died en route. All three boys fought in the Revolutionary War, but only the eldest, John Pitner, survived.
At the time that our John Pitner was married and living in Rockingham County, Virginia, there was another John Pitner living in Newton Township, Bucks County Pennsylvania, (who had a son named Henry, and a grandson, Lambert). I don't yet know of a connection between these Pennsylvania Pitners, and the Virginia Pitners who headed to Tennessee and then split off to Georgia and Illinois, with some branches staying behind.
Two John Buttners arrived in Philadelphia in the 18th century, one on November 2, 1752, and the other on August 23, 1773. A cousin of my husband, Don Pitner Smith, whose research I am here citing, believes that the Virginia John Pitner was the first, John Christoph Buttner, who arrived in 1752 on the Ship Phoenix, John Spurrier Commander.
If anyone out there speaks German, there is apparently a manuscript in the Mormon library, Deutsches Geschtechlerbuch, Vol 89, pp. 27-70 which is a genealogy of the Buttner family in Germany. Apparently the Buttner family examined in this text did at one time live in Coblentz-on-the-Rhine.
So, there's plenty to research on both ends, figuring out the older generations, and figuring out how the newer ones fit into the big picture.