If you have a specific question pertaining to
McDonough County history,
send your question, with as many details as possible to
mcdonoughhistoricalsociety@gmail.com
For county historical information see
A great resource for McDonough County historical information is the Archives and Special Collections Unit of the Malpass Library at Western Illinois University, Macomb, Illinois.
http://www.wiu.edu/library/units/archives/
Another great resource of information is the McDonough County Genealogical Society
An excellent resource for information about the early history of the county is
The History of McDonough County by S. J. Clarke.
Google has digitized this book, and it is fully "searchable".
You can also read this same volume online in a slightly different searchable format at
http://www.archive.org/details/historyofmcdonou01clar .
Sources of Information about McDonough County History (many of them online sources) can be found here: http://mcdonoughhistory.jimdo.com/mcdonough-county-history-sources-of-information/
[or if you prefer, write to the Historical Society, Box 83, Macomb IL 61455]