Just a quick note concerning obtaining copies of the book "Life and Labors of John Seybert, the First Bishop of the Evangelical Association."
I did extensive research into the family back in the 1970's. At that time I lived in Lancaster County, PA. By going to book sales and contacting dealers, I was able to buy about six copies of the book.(Which I passed on to other interested family members.) In addition to the English version, there is a version in German. I imagine the book is still available and with the wonders of the internet, should not be hard to find or seek.
The Henry Seybert barn still stands in Sporting Hill outside of Manheim PA. My wife's family was descended from the Bishop's brother which kept moving west to Ohio, Indiana and Michigan. After our marriage,I brought her back to her roots in Lancaster County where my family dated back to the 1850's. The local press did a nice article on her and my two sons (8th generation.)
Unfortunately, I do not have my research material where I now live in Fargo, ND. However, all of my info and much more is in the hands of Jack Seybert and Barb Wunder who have responded to this forum.
Bottom line is that the book can be found and is a wonderful keepsake.
I repeat Barb's request for more information on which of the Johann Seyberts of Hessian soldier fame, is the father of Henry and grandfather of the Bishop.