1872, folded letter datelined Arroyo [Puerto Rico], carried privately to the Danish West Indies or via the British local line that traveled around the southern coast of Puerto Rico, franked at St. Thomas with perforated 2d. blue horizontal pair, plate 13, cancelled by St. Thomas PAID “A” C51 duplex (13 Jun), endorsed “p. Amr. Str. / from St. Thomas”, to New York, with “N.Y. STEAMSHIP 10” (19 Jun) transit c.d.s., having been carried on the Merrimac which departed St. Thomas for New York on 13 June, a quicker routing than the British mails via Havana, light filing folds, one through pair, else a fine and important cover; illustrated in Engstrom, “Danish West Indies Mail 1754-1917”, Vol I.
Conveyance of mail as illustrated by the cover offered here was handled under the terms of the 1868 Anglo-American Postal Treaty; only British mail destined for beyond St. Thomas was permitted to be carried by United States packet.
