King of Prussia and first German Emperor who, along with Otto von Bismarck, oversaw the unification of Germany (1797–1888). LS in German, one page, 9 x 11.25, September 2, 1873. Untranslated letter to General Carl von Hessen, informing him that his aide-de-camp, Major Von Zangen, has been promoted to the rank of colonel. In fine condition, with central vertical and horizontal folds. RR Auction COA.
