Electronic but not free -- Marshall and Putnam counties, Illinois

At Wholly Genes Archive CD Books USA offers for $14.95 a download of the unindexed but now every-word-searchable book:

Ellsworth, Spencer. Records of the Olden Time; or Fifty Years on the Prairies Embracing Sketches of the Discovery, Exploration, and Settlement of the Country, the Organization of the Counties of Putnam and Marshall... Lacon, Ill. : Home Journal Steam Printing Establishment, 1880. 754 pages.

Don't bother with my summary when you can read one from Barbara Vines Little, CG.