There were multiple family death notices (and an obit. for Herman) published for this couple in Milwaukee's German language newspapers. I've indexed them in the collection "Milwaukee's German Newspapers; an index of death notices and related items" (1844-1950). I've also indexed early death notices for at least two of their children: "F. B." (1860s), and Hermann Jr. (1870s).
There are currently about 175 entries of the Berger name indexed since the project was organized in 2007 and indexing continues today. Other surnames referenced with Berger include: Koch Crass Grebe Ortlieb Griep Stolte Schlosser Schmiedtgary.firstname.lastname@example.org