Many resources here - main library in Lincoln, Nebraska, and CDs of genealogy for sale (to reimburse them for their costs in producing). Much of the genealogy in Russia has been worked on and immigrations found and links made to US census - it seems possible the answer can emerge.
I do not mean to suggest that the above represents every database of names of Germans from Russia!
Find-a-Grave and U.S. Census, many Blumhardts in Edmunds County, South Dakota, including
Karl G. Blumhardt b 1843 - d 26 Feb 1918 His wife Mary Kilber b 23 April 1843 - d 13 July 1912
Read about the history and the late nineteenth and early twentieth century of persecution of Germans in Russia. Many emigrated; many left behind perished or lived out their lives in forced labor camps.
The Germans in Russia lived on a great plains and in USA they tended to settle in colonies in Nebraska, Kansas, the Dakotas, etc.