1855 (Feb. 20) Mainz, Hesse-Darmstadt to Boston, Mass., mourning cover with "Mainz, 20 Feb 1855" double circle date stamp, black "PD" paid direct h.s., large circled "P." prepaid h.s., red London (2.23) transit and red manuscript "16" credit to the U.S., carried by Collins Line Pacific from Liverpool Feb. 27 to New York arriving Mar. 14, "Boston Am. Pkt. Mar 15" backstamp and matching "5" cent due rating h.s., Very Fine. Estimate  $150 - 200. Prepayment shown lower left in magenta ink, 9 kreuzer internal and 38 kreuzer (or 10¾ silbergroschen) for transit fees beyond the German-Austrian Postal Union under Anglo-Prussian Convention of 1852. British credit included 8d transatlantic and 4d British internal fees. Since American packet carried letter across Atlantic, G.B. credited 16¢ to U.S. $0 (Image)