The financial log covers day-to-day expenses and income from 1889-1917 when the group dissolved. This is written in the German language.

The membership log, 1862-1905, contains three distinct sections, all in chronological order: a membership section of adults when they joined the congregation and some vital statistics (1870-1905 pages 1-17); a list of families with birth dates of children (1869-1905 pages 84-121); and then what seems to be a list of those interred in the congregation’s burial site (1862-1905; pages 142-151). This book is written in the German language and contains a lot of genealogically rich information.

Minutes (1869-1917), although not the original, were copied by Bob Selbrede of West Salem. This translated and transcribed version of the Freethinker minutes was preserved in the Hamilton Mausoleum records.

Newspaper clippings include an article written by James O. Holmlund (1964), as well as copied obituaries of many Freethinker members.

The personal correspondence (1881-1949) was written to Mr. and Mrs. Louis Sander and their daughter Hulda and is not necessarily directly related to the Freethinkers. However, one of the letters from a niece in 1914 mentions a proposal of the Hamilton Mausoleum. Also a letter written in German from someone in Watertown, Wis., is likely related to the Freethinker movement. Most of the correspondence is written in the English language, except three letters.