I think we have a match here! How are you connected to these Radkes/Radkeys? Reply by direct e-mail re this aspect, if you prefer.
My maternal grandfather was Lawrence Bartholomew Radkey, b. 8/24/1879 in Harrison Twp., Cass Co., IN. He died in 1959, at which time, alas, the Radkey family Bible was sold to an antiques dealer (along with a lot of other stuff)! All my info is from the gen. work of a late uncle, done in the 1950s-60s, and a page of Radkey names is missing from my copy. I have verified none of it yet, but I have found occasional mistakes or typos in other places. I'd be very much interested in accurate info, esp. for Prussia/Germany.
His father was Henry Simon Radkey, mother Mary Fredericksdorf. Henry was the eldest son of Lorentz Radke/Radkey, of Deutschkron, Germany, b. 8/10/1822, d. 4/7/1893. Henry's mother was Anna Maria Tickfer of Usht, Germany, b. 11/20/1832, d. 3/15/1900. Presumably, they all died in the Logansport area. Supposedly, they came to the US just before the Civil War, and Lorentz served on the Union side.
My info says Henry Simon Radkey was born Oct. 29 (not 2), 1855, "at Usht, Schneide, Muehl Province, Brandenburg, Bromberg-Posen, Germany." My mother (age 95) always just said he was from Posen (now Poznan, Poland). "On May 8, 1876 he married Mary Fredericksdorf, an American girl, born December 23, 1858 and who died January 31, 1946." Following that sentence is this one, and I can't tell for sure to what parents it pertains—Lorentz and Anna Maria? "Other children were Anna, twin girls Mary and Bertha, Andrew, Robert and another girl whose name is unknown to us...."
Henry and Mary had 7 children: John, Lawrence (my grandfather), Robert, Henry, Andrew, Derena, and Leopold. There is some text info about the descendants of some of them and a reference to other names' being in the appendix (where one page is missing). Leopold never married.
My grandfather, Lawrence, went to Chicago at about age 14, to work at a railroad job. He met my grandmother, Inabelle (Belle) Budd, because he stayed at a boarding house kept by her mother in/near West Pullman, Chicago. They were married 7/24/1901 and had 2 daughters (1902, 1905) and 1 son (1920). The last had 5 children, 4 of them boys, hence with the surname Radkey, and his daughter is not married so still carries the name.