Try looking for the family name in or around St. Mary's KS. My great grandmother's maiden name is Eberhardt but I do not know what the first name was. There were Eberhardts living in St. Marys, Pottawatomie, KS. According to a census (sorry, I cannot remember which one) they lived next door to my grandmother's brother Michael Martel & his family. Most of the people in St. Marys were Volga River Germans (Germans whose families went to Russia under Catherine the great to farm in the Volga River valley. http://cvgs.cu-portland.edu/index.cfm
The Germans who settled there were primarily Catholic from Russia. This could be the area to look.
Good luck & best wishes!