Alan,
Here are a couple of websites that won't answer your specific question, but in general, give you some idea of Illinois during that time period.

IL Trails-- <http://www.iltrails.org/> Carthage is in Hancock County, which will be in the "Central section" of that page. Also under "State" databases, you'll find an article (with good sources) done by someone at SIU on the underground RR.

IRAD at Western IL University has some of the old Circuit Clk. books listed. These are often duplicates with one set of books remaining at the local Courthouse. A person from the local historical society at Carthage may be able to look up the cases for you. <handcockhistory@yahoo.com>

Also, the old Quincy, IL newspapers are online for that time period. Their main page is at <http://www.quincylibrary.org/Reference/NewspaperArchive.asp

Ann