1857 (Aug. 7) Charleston S.C. to Nantes, France, blue docketed folded cover from the Garnier correspondence bearing 1¢ blue (9) pair, large margins except touch at top left, and 3¢ dull red (11A), black "New York '6' Aug 11" debit exchange cds, carried as endorsed by Cunard Line Europa from Boston Aug. 12th to Liverpool arriving Aug. 23rd, Calais (8.24) entry cds with "16" decimes due rating handstamp, Nantes (8.25) arrival backstamp, Very Fine. Estimate  $300 - 400. The new U.S. France Treaty went into effect on April 1st 1857. The basic rate was 15¢ per ¼ ounce, which could only be fully prepaid or left unpaid at the originating post office. No provisions were made for partially paid letters. There were two routes the mail could travel, via England by American or British packet and then British mail over to France, or directly to Havre by American packet. $0 (Image)