The Antiquities of Wisconsin (I. A. Lapham, 1855)
Lapham, I. A. The Antiquities of Wisconsin, as Surveyed and Described. Smithsonian Contributions to Knowledge, vol. 7, Washington: Smithsonian Institution, 1855. University of Pittsburgh copy via the Internet Archive, archive.org/details/antiquitiesofwis00laph.
What the corpus of Lapham's Antiquities of Wisconsin holds, how it was built, and the two plates of Beloit's mounds.
Transcribed page by page: 48,616 words. Each page keeps its printed page number, so every quotation on the site can be checked against it.