Check out www.berger-family.com They have a map you can download of Germany w/Prussia marked in the upper right hand corner.
would you happen to have any info on Frederic Fritz Berger , also born Prussia about 1844? Don't know when he arv'd in US, but re' my info, his mother Christina (b. abt 1827) & 2sib's ended up in Gasconade county, MO where he mar'd Ella/Ellen Brumley? (b.1849-1921) abt 1871. Both are buried in Berger Family Cem', Saline Co,Mo. They are my husband's maternal gr'parents. I also have been unable to trace their origins, but I have info on their 8 children & 9 Gr'children + photos of most of their gravestones. My husband, Hansel Burks & 1 sister are the only living members of the immediate family. I will be happy to share if interested.