Wilson, Douglas L., ed; Davis, Rodney O., ed. 'Register of Informants' in 'Herndon's Informants: Letters, Interviews, and Statements About Abraham Lincoln' . Urbana: University of Illinois Press, 1998. [format: book], [genre: history]. Permission: University of Illinois Press
Persistent link to this document: http://lincoln.lib.niu.edu/file.php?file=herndon737.html

Irwin, a Republican and minor public official living at Pleasant Plains, helped WHH identify and locate Lincoln-era informants in Sangamon and Menard Counties. (Power; Federal Census, Sangamon County, 1850, 1870; Walsh; letter from Mark D. Irwin, July 15, 1992)