The Bergey Family was among the first Germans to arrive in the America, and were one of the founding families of the first Mennonite Meeting Houses in Germantown, PA, then Salford, PA and Telford, PA and beyond.
An early ancestor was John Bergey, 1781-1860, and like many Mennonites from Salford and Telford, they migrated to Washington County, MD, then many of their descendants went to Morrison's Cove, PA, Somerset County, PA, the Ankneytown, Ohio, the Indiana and Points beyond.
Many Bergey's still live in Montgomery and Bucks County, PA.
Best suggestion is to visit the Mennonite Heritage Center; 215-256-3020 info@mhep.org at 565 Yoder Road Harleysville, PA USA They can actually guide you to see the land the Bergeys owned originally, and where the Bergeys live now.
Bergey is a very prominent name in that area.