Can anyone help me unravel the Dueker/Duecker Family that was located in the Redbud Twp of Randolph Co., Illinois ~1860-1880. The name is spelled Duecker for some in the 1880 census but found as Dueker in other places.

I am decendant from Isac Dueker (b. 1860) who moved to Gasconade Co., MO abt 1885. I believe his father was William Duecker [sic] (b. 1838-Prussia) who was in Randolph County, Ill in the 1870 census. He was Married to Eliza A. ?. After William's death in 1872, she remarried to Edward Dennis and raised William's children with him. Eliza, Edward Dennis and William Dueker (Duecker) are all buried in the Nelson Cemetery in Randolph Co. Ill.

That's the short version. Any help untangling this clan is appreciated. I'll be happy to share any info and/or suspitions I have. Thanks in advance.