1837 (Mar. 20) New Orleans, La. to London, England, folded cover endorsed "Express Mail" with blue "New Orleans La. Mar 20" cds with matching "Paid" h.s. and red manuscript "75" rating, carried by Swallowtail Line Ontario from New York Apr. 3 to Portsmouth arriving Apr. 24, "Portsmouth/Ship Letter" stepped h.s. and manuscript "1/4" 1s4d due rating, London (4.24) arrival backstamp, file folds, Very Fine, scarce express mail transatlantic usage. Estimate  $400 - 600. Express mail rate was triple or 3x25¢ = 75¢ from New Orleans to New York. Postage due consisted of 8d ship fee plus 8d inland fee for 72 miles from Portsmouth to London. $0 (Image)