This work includes most of the featured individuals found in Mr. Power's book on Sangamon County.  There were a few people inadverdently overlooked but you will find the index here mostly accurate. 

I listed each individual, the year they first entered Sangamon county, the place they came from preceding their arrival and the place mentioned in the book as their point of origin.  For most, this place of origin will be their birth place.  For some, it is simply the first place mentioned in the book.  For many, the place of origin and the previous place lived is the identical.  For some, they lived more places than those two mentioned.

This list can be used to find out which families arrived in Sangamon in the same year, which families came from the same locations.  I suggest that you make use of the Find feature found under your Edit tab.  Hopefully this will give you some leads by seeing what relationships might have existed among your ancestors.

Enjoy the puzzle!