Mails between California and Britain at the 1851 Treaty Rate. Envelope piece endorsed "S. Francisco Sep 20. 1855" addressed to Brighton. Carried in the closed bag and on a U.S. contract vessel to Liverpool; portion of reverse opened for display, Very Fine. Estimate  $750 - 1,000. On 1st July 1851 the rates for mails to Britain from the West Coast via New York were reduced from 59 cents (2 Shillings 5½ Pence) to 29 cents (1 Shilling 2½ Pence). The Treaty provided the United States with an additional 5 cent (2½d Sterling) for the inland postage over and above the 24 cent (1/-Sterling) for the packet rate. A 1/2½ handstamp was issued to Liverpool in February for the California mails.Carried on the following route and vessels:- San Francisco 20th September 1855 to Panama 4th October on the S.S. Sonora (Pacific Mail Steam Ship Co.).Aspinwall 6th October to New York 16th October on S.S. Empire City (United States Mail Steamship Company).New York 17th October to Liverpool 28th October on S.S. Pacific (Collins Line) [New York & Liverpool United States Mail Steamship Company]. $0 (Image)