In the last year, I have moved into postal history. By far, the most interesting classic covers (in my opinion) are the various international usages. This is my top acquisition to date (courtesy of Siegel Auction earlier today).
With all of this build-up, I hope that the backside has something to offer....quite honestly, I bid on this solely on the merits of the front of the cover. I have yet to examine the cover in-person, and I'm as clueless as everybody else as to the contents (if any) of the reverse side.
Here is some additional history of this cover, for any one who cares: The payment of 40 cents represented the full United States postage including maritime transfer up to the port of Veracruz for a fourth weight step letter. The handstamped "7" (Reales) was applied at Veracruz and represents the assessed Mexican inland postage rate. After contracts with Edward H. Carmick (1852-56) and C.K. Garrison (1857-58) lapsed, the Postmaster General of the United States ordered a third temporary contract for mail service between New Orleans and Veracruz to Charles Morgan, of the ship Tennessee II. This third contract began service on November 1, 1858 and lasted until February of 1861, when Louisiana was admitted into the Confederacy, and Tennessee II was confiscated to be refurbished as a war ship. This cover was carried by Tennessee II in the period covered by Mr. Morgan's contract, and thus is a rare maritime cover of which very few exist. (Information courtesy of Sergio Sismondo)