What area of Bohemia could have been considered Germany in 1900 and Austria in 1910 ?

I have been looking for clues. I see that there was also Frank Wollman born 1820 in Bohemia who immigrated around 1863 and lived in Michigan. He could have been related. He finally ended up in Detroit. He says he is from Bohemia in 1870 and 1880. Then on the 1900 census when he has passed away his son says his father was from Germany.

I was looking on the LDS website and I saw some Wollmans in Hennersdorf, Deutsch Gabel, Bohemia. (Where is that?) One was Joseph Wollman born in 1811. At that age he could have been the father of my Henry Wollman. I have never found an entry for Henry Wollman born around 1830 - 1835.