My great-grandfather's name is Proctor Oneske. He was born in the Brest province of Grodno, Poland on July 12, 1881. He immigrated to the USA and settled in Detroit, MI in 1912. While passing through Ellis Island, his record shows a name change from Prokop Oneskewicz to Proctor Oneske. His first military draft card shows another variation, Procope Oneskevitz. I'm thinking Oneskewicz is likely as it contains the traditional "wicz" which in Polish I believe to mean "son of," so "son of Oneske." In the US he met and married Sophia Drust who appears to have spoken the same language (Russian? Polish?). She too is a mystery.
But in over 10 years I can't track down any records of his life in Poland or any ancestors. All I know is he had at least one brother in either Poland or Russia who he anxiously called during the war to check his welfare. I would be very grateful for any help!