Frederick GUENZLER parents

I have:

H: Frederick GUENZLER
B: Mar 22, 1850 in Mosbach, Bavaria
D: Jan. 11, 1930 in Mt. Carroll, Carroll, IL
M: Mar 29, 1875 in Jo Daviess, IL
W: Christina Marie KELLER
B: Aug 15, 1851 in Mosbach, Bavaria
D: Jan 7, 1911 in IL

Children:
Frances Josephine, Madie (Martha) Emma, Samuel Andrew, Louis Frederick, Matilda Rachel, Fred George, Laura Katherine, and Marie Christina.(My line descends from Madie Emma.)

I am told his parents were:

Samuel LeGUENZLERE or GUENZLER (depending who was in power (??)) and Olga BEYER.Samuel and Olga also had son John b: Ot 7, 1848.

Any help?Thanks!