Thomas Dunnell of Clinton, Ill./ New York

I am searching for information on a Thomas Dunnell. I believe he was born in either Canada or New York. His wife, Mary was from New York. They eventually moved to Clinton County, Ill. In the household in 1870 were two children named Edward Harris, 11 and Elizabeth Harris,9. I am looking for more information about the kids. Anything will be appreciated. Thanks, Ann Stephenson