1856 (Jun. 30) Hamburg to New York, N.Y., folded cover with "Schieffsbrief-Post Hamburg 30 Jun 1856" rimless postmark and manuscript "6" schillinge prepaid rating, carried by Hapag Line Hammonia from Hamburg Jul. 2 to New York arriving Jul. 18, New York "6" cent due rating, Very Fine, One of only four recorded covers carried under the U.S.-Hamburg informal agreement prior to the 1857 Treaty. Estimate  $300 - 400. While an informal agreement between the U.S. and Hamburg had been concluded for mails to be carried between Hamburg and the U.S. on the HAPAG steamers, and the letter sender paid the appropriate fee (equivalent to 10¢), New York's treating this letter as an incoming ship letter indicates they had not been advised of the agreement by mid-July 1856. $0 (Image)