U.S. and Worldwide Stamps and Postal History

1866 (10 Oct) FL from a military camp to Buenos Aires, with oval "Sin Campo" handstamp, contents mention "Los Paraguayaos" and other military references, fine cover used during the "War of the Triple Alliance" (a military conflict in South America fought from 1864 to 1870 between Paraguay and the alliance of Argentina, Brazil, and Uruguay. It caused more deaths proportionally than any other war in modern history, and particularly devastated Paraguay, killing most of its male population)
Estimate: $1000