It's difficult for anyone to help you without any dates or approximate dates and first names.
You might want to try the free search tool at https://familysearch.org/
where you can plug in names, events - b,m,d, residence etc., spouses, parents etc.
Below is an example using Name: Whitehead; Event: Any; Date range: 1840-1940 Location:Fulton (county), IL
https://familysearch.org/search/records/index#count=20&query=%2Bsurname%3Awhitehead~%20%2Bany_place%3A%22Fulton%2C%20IL%22~%20%2Bany_year%3A1840-1940~
Which came up with 16,374 results ! Maybe some of the names listed are your ancestors.
Good Luck