Looking for Harris Family IN Illinois

After searching for many years I finally discovered my Bates roots in Illinois, However my grandfather's maternal side is another puzzle. My great grandparents were Ezra Bates and Matilda Harris. Matilda's parents have eluded me. From census information I know Matilda was born in Illinois. Ezra and Matilda's first child Serepta was born in Effingham Co., Illinois in 1849. In 1860 they were in the Cumberland Co., Illinois census with children Serepta, Willard, Harriet, Melissa, Edgar. In 1870 they were in Big Springs township, Shelby Co. Illinois, with childrn Willard, Harriet, Melisse, Edgar,Clinton, Grant (my grandfather) and Henry. Ezra I assume passed away before 1880 because Matilda married John Cornwell and they were in 1880 census Paradise Township, Coles Co., Illinois. Two children were listed with them My granfather Grant and Clinton. What happened to Henry who would have been 10 years or less?? 1880 census also said Matilda's father was b in Virginia and Mother in Kentucy. In 1900 Matilda is in the household of Grant in Marion Co., Kansas. She is listed as a widow and 75 years old.
Matilda died in 1907 in Mulvane, Coles Co., Illinois but was buried in Burns City Cemetary, Marion Co., Kansas . Beside the grave of John Cornwell. I think she was probably visiting children or relatives in Mulvane or perhaps moved back after Johns death. Please help if you have any information about her people. I'd be so grateful.