Affidavit of Abraham Lincoln and Oliver Diefendorf, 4 January 18491
This day came before me the Hon. A. Lincoln and Oliver Dieffendorf and made oath that they were well acquainted with Joseph Newman, deceased, who was a private in Col. Baker’s regiment of Illinois volunteers who died in Mexico, in Battle,2 and also with Henry Newman, his father, of Sangamon County, Ill. They state that the deceased was very young, and never married, to the best of their knowledge and belief.
(Signed) A. LINCOLN.3
1The typed transcription is the only text of this affidavit to have been found. It may be incomplete. The original was advertised and listed by F. H. Sweet in List No. 52 (1939), Lot No. 109. A copy of Sweet’s list has not been located.
2Joseph Newman died in the Battle of Cerro Gordo.
Sangamo Journal (Springfield, IL), 20 May 1847, 2:1, 2.
3Henry Newman was eager to get the back pay due Joseph Newman for his service in the Mexican War, and he wrote Lincoln a letter in December 1848 appointing Lincoln as his attorney and essentially giving Lincoln his power of attorney to secure the money. A war veteran himself, Diefendorf had established an office in Washington, DC to settle claims for bounty lands, extra pay, and pensions due soldiers who participated in the war. Presumably Lincoln and Diefendorf appeared together at the War Department to give testimony in the case. The person before whom Lincoln and Diefendorf testified--the author of the affidavit text--is unknown.
Illinois Journal (Weekly) (Springfield), 3 October 1848, 3:5.

Typed Transcription, 1 page(s), Abraham Lincoln Library and Museum, Lincoln Memorial University (Harrogate, TN).