Looking for Fiihr of Iowa and Germany

My Surname FIIHR is my maiden name. It is actually spelled F, umlote U, H, R (the German "way"). When my grandparents came over from Germany, the Umlote, U, was not in the "Anglo/American" way of spelling. My grandmother chose 2, "I"s because when you write it in 'cursive' it looks like an umlote "U". I wish that she just kept the "U" because it would have made it so much easier! If she wanted the 'dots' over the "U", then, she could have just added them!
When my grandparents came to "Stanton Island", they ended up in the midwest in Iowa.