Page 115 - Charles Shreve - William H Gross United States 1847 Issue

C. British Isles Retaliatory Rate
1. England Contract and Non-Contract Ship Mail

The British tried to reclaim the monopoly on Trans-Atlantic mail after American Packets began carrying mail in 1847.
They required that the usual British Packet postage (11- or 24~) be paid on mail carried by American Packets.

OC 31, 1848 to Sheffield, England (November 14). e
3W pays the 5~ domestic rate and the 24~ Trans-Atlantic rate (1~ overpayment). The payment was disregarded and 1 I-
was collected from the addressee. Carried on the packet Niagara (Boston November 1- Liverpool November 15).
Earliest recorded 10tf use by the US Express Mail/New York route agent

JY 8, 1848 to Blackburn, England (August 9).
Mailed during the "Retaliatory Rate" period when prepayment of 24~ postage was required. The New York post office
could not forward the letter by British or American packet so sent it by private ship. It entered English mails at Liverpool
as a ship letter and charged 8d. At either Liverpool or Blackburn it was discovered to be double weight and charged 1 I 4d.