U.S. Postal Agency, Cali, Colombia, massive collection of approximately 240 covers with backstamp transits including some proof strikes and 13 predecessor U.S. Postal Agency Barranquilla Colombia, proof strikes of the exceedingly rare "Air Mail" cds and also a Jan. 31st 1942 use on the last day of the Cali agency, variety of South American origins, Very Fine and impossible to duplicate. Estimate  $2,000 - 3,000. During the early days of scheduled airmail flights, flying was limited to daytime hours, and on the routes from the United States via Central America or the Caribbean Islands to South America, Cristobal was a convenient overnight stop. Pan American Airways (PAA) handled the mails to Cristobal and the air fields along the circum-Caribbean and thence to Montevideo and Buenos Aires via Brazil. Pan American-Grace Airways (PANAGRA) carried the mails down the west coast of South America and thence to Buenos Aires. Pan-Am changed the flight schedules Sep. 1st 1940 to run Miami-Cristobal-Cali, requiring the overnight mails be worked at Cali instead of Cristobal. This necessitated the U.S. Post Office to open an agency at Cali. The agency accepted no new mails, just processing transit mails. $0 (Image)