Randolph county is quite important in early IL history, since it's the site of the first state capital. I'm not sure what type of history is being sought for the period from 1960-2000.
Thanks for that information, muon2.
Her main focus seems to be looking at voting patterns there - trying to figure out its partisanship and which issues have motivated voters there over the years. The area has somewhat swung Republican at the presidential recently, despite being pretty solidly Democratic for other offices, and it voted for Perot in 1992 and Wallace in 1968 in greater proportion than did the rest of the state. So I guess she's looking into these anomalous sorts of tendencies.