Tabor Abolitionist History
https://www.nps.gov/nr/travel/underground/ia1.htm
The history of the Underground Railroad in Tabor, Iowa, upon which Gilead is based.
Congregational Library and Archives
http://www.congregationallibrary.org/about-us
Resources from the Congregational Church—John's denomination.
The Gilead Society
"A collection of material for fans of Marilynne Robinson"
Iowa History
http://publications.iowa.gov/135/1/history/7-1.html
A record of Iowa's history from the Iowa Official Register.
Robinson's NYRB Essays
https://www.nybooks.com/contributors/marilynne-robinson/
Robinson's essays published in the New York Review...
