The WIKITREE profile for John Schoeppner has everything you suggest, including WHY I believe he was born in Darmstadt, Prussia.
It is unlikely that he was born in Bavaria, as the Naturalization record suggests. There are several other John Schoeppners to whom this record might refer.
I think he was born in Darmstadt because his son John's 1920 census said that he was; other censuses including his own merely state that he was born in Germany.
I personally visited Germany about 2010, and I went to the present city of Darmstadt, south of Frankfurt. There I spoke with an aide, working in the archives in Darmstadt, who helped me try to find my John. There were NO Schoeppners in Darmstadt. He suggested that my John likely lived in Darmstadt in the previous state/country of Prussia. In the early 1800s, Darmstadt WAS a city in Prussia, he said, and there were some Schoeppners living there many years ago. This is why I suggest that my John was born NOT in the present city of Darmstadt south of Frankfurt, but in Darmstadt in what WAS Prussia. This is all outlined in my Wikitree profile for John.
So sorry that my G2G question did not specify as much as there is in my Wikitree profile of John.
I transcribed EVERY bit of information that I could find for John Schoeppner. I went so far as to try to decide if the John listed was MY John or a different John. Other John Schoeppners moved to the middle part of the USA, and MY John stayed and died in New York. This fact makes my search even more challenging, given that there are several additional Johns born in Germany.
Someone suggested that I should find out when and where John married Josephine. No record anywhere in New York. His children apparently were not baptized in New York, as no record can be found for this information.
As I said, I have been searching for 20 years, and even a trip to Germany did not uncover his birthplace. I am not perfect, but I did as much as I could think of. I have even visited some of the churches in the area of Darmstadt (Prussia) where Schoeppners lived. I plan to visit again and visit additional churches.
You have been very critical of my efforts to try to find my g-g-grandfather in Germany. I did not try to justify WHY I discovered what I discovered with my research. That would be too voluminous for this G2G question.