It is clear that there was a Henry Stahl who died in what is now Franklin county, PA in 1790. The letters of administration for his estate were given to his sons. However, trying to establish who Henry's father was has been a nightmare.
According to a 1945 publication by Lillian Hull (or, in her not very helpful words, "history tells us..."), Henry's father was Henry Eugene Stahl, a Mennonite who settled around Pequea Creek in (then) Chester and (later) Lancaster county, PA in the early 1700s. He is reputed to have come from Switzerland in 1712 and to have lost his wife and 3 children on the 5-month (!) voyage.
No documentary source was cited for this information and there are no primary (or even secondary) sources that can back up that claim. In published sources for Lancaster county with specific reference to Mennonites, there is no mention of a Henry Stahl in the early settlers there. The same is true for listings of the original settlers in Pequa. And there aren't any tax or land records, probate records, or burial records pertaining to a Henry Stahl in either Chester or Lancaster counties. I find it suspect that someone who supposedly arrived in 1712 failed to leave any record for more than 40 years.
In the meantime, it seems as if everyone who posts genealogical information on this branch of the Stahls makes this claim, sometimes citing the same 1945 source as gospel, and sometimes simply repeating what other people have done. Unfortunately, copying unverified and erroneous information simply perpetuates the original error.