Lawyer who served in Lincoln’s cabinet as postmaster general (1813–1883). Civil War–dated partly-printed DS, signed “M. Blair,” one page, 7.75 x 9.75, February 28, 1863. Blair authorizes a gentleman “to frank Official Letters and Packages of Blanks and Documents which may be deposited in your office by Amos Norcross, Assessor of Internal Revenue.” In very good condition, with multiple horizontal storage folds, various irregular blocks of toning, and some small areas of paper loss to corners and edges. RR Auction COA.