Abraham Lincoln frequently signed letters and documents with the familiar abbreviation, "A. Lincoln." A document with a full signature ("Abraham Lincoln") is listed on eBay for $21,000 with offers accepted.
The autograph is from a document dated May 7, 1861. In it, Abraham Lincoln appoints Joseph J. Coombs of the District of Columbia as Examiner-in-Chief of the US Patent Office. The document is 13-1/4" x 17" and is framed. Lincoln's signature is about 3" long. The document is also signed by Caleb Smith, Secretary of the Interior.