My mother was cousins to the Schiesman family, many are buried in St Joseph Cemetary in Rio WI. Mark Schliesman was born in 1904 and married my grt aunt Adeline Warmke. Mark Schliesman's father was Henry born in 1873. Henry's father was Michael born in Germany in 1834, his father was Johann born in 1801. I don't see any Williams but wonder if they are somehow related back in Germany. Several yrs ago before her death, my grt aunt Sr Norene Warmke used to visit her Schliesman cousins in the Sun Praire, Bristol area but don't see any listings for them in the phone book. Most likely they have have died. Anyway there are Schliesmans in Beaver Dam and Rio areas.
Hope this helps.