I recently found the marriage record for my Charles Keppers, and it is in the surname Koeppers. Exactly when it changed to Keppers I don't know. They immigrated to IL before 1870 census; the 1880-1930 censuses found them in IA, mostly Wright Co. Doyou or your friend have any ties to this branch?
Charles/Carl/Carollus married Magdalena Kremer, 10/1845, Brandscheid, Rheinland.
They had the following children, all born Brandscheid: Christina, born 10/1846 Anna born 9/1848 Petrus, born 2/1850 Mathias born 4/1853 Catharina born 6/1856 Margaretha born 3/1859 Anna born 8/1861
The youngest Anna is my great-grandmother. She married Mathias Schwickrath/Swegrath. he died young, and Anna married jacob Wilfers. I have a lot more current info, so if there are ties, let me know.