(Retaliatory Rate) 1848 (Oct. 3) New York N.Y. To London, England, blue folded duplicate letter from Grinnell, Minturn & Co. that was carried privately as endorsed on one of their ships of the Blue Swallowtail Line Henry Clay from New York departing Oct. 8th to Liverpool arriving Oct. 26th, black "Liverpool Ship 26 OC 1848" backstamp with manuscript "1/4" double-weight ship letter rating, red London (10.27) arrival backstamp, Very Fine and interesting use bypassing the retaliatory fee. Estimate  $300 - 400. The original of this letter went by Cunard Line "Acadia" from Boston on Oct. 4th, which would explain the explain the explanatory note on the 1848 Reprisal Act added as a postscript:"You will notice a high charge of postage, but under the existing postage arrangements of the two countries, high rates are charged on both sides - Here we have to pay 24c per ½ ounce & 48c per ounce when the mail leaves this port & from Boston the charge is 29 & 58 cts including the inland postage of 5c pr ½ oz.". $0 (Image)