My Boehlke ancestors came from Prussia between 1850-1860.Settled in Oak Creek (Milwalkie), Wisconsin then moved on to Prairie du Chien. My g-g-grandfather's Johann Wilhelm Boehlke and Wilhelm Sauer both died in Prairie du Chien and are buried there with other famiy members in the Evergreen Cemetery.From there the family moved to Deadwood, SD in 1880.There are so many Boehlke's that it is always possible somewhere back there we are connected.Unfortunately, I have not been able to research prior to entry to the U.S.
We have also had many family stories about being related to Oswald, and like Judy have researched and bought books about him.There is also a display about him at the Air and Space Museum at the Smithsonian in Washington, DC.We have yet to find an actual connection.
There is a gentlemen by the name of Leroy Boehlke who has written several books regarding German immigrants to the Wisc. area and is very knowledgable re: Boehlke's in Wisc.If you search the Web on his name you can find several sites that might provide you with some info.The last I knew Leroy didn't use e-mail so you would have to write him via Snail mail.Happy hunting !!!