Any Chance that William Voss is connected to Christoph Voss who immigrated to the Wisconsin, Sauk Co in the 1850's? He was also from Mecklinburg in Germany.
How far back have you gone?
The Voss's in Wisconsin changed their name to Foss... I just ordered a Y-DNA test on FTDNA and I am awaiting the results. Voss is on my direct father line.