This is essentially two separate volumes packaged together in this edition. The Historical Encyclopedia of Illinois is 608 pages. Over half the entries appear to be biographical, and the majority of the rest appear to be towns and counties.

The portion of the volume for Knox County has its own Table of Contents on page 609. Part 1 is on the county, Part 2, at over 100 pages, is on Galesburg, and Part 3, at over 150 pages, is on towns and townships. There are biographies within all three sections and numerous portraits.