NOTE: Use historical maps to determine County names.  Depending on the year from 1854-1925, Nebraska counties were being formed, which means county lines and names were being changed. Researchers can use:  https://www.mapofus.org/nebraska/ to see the formation years of the Nebraska counties and map abbreviations. It also has a modern map overlayed on the census years from 1860 through 1910-1930.

Ancestor map

Foreign Born Czech population in Nebraska