This is a nifty cover(official, 5-C. U.S. PSE of the U.S. Consulate is open on more than 2 sides, has a pin hole in it, and has some stains and creases here and there; back flap is 80-85% intact) sent sometime before December 17, 1879, from someone connected with the U.S. Consulate at Colon, Aspinwall, United States of Colombia(or U.S. Navy, as Aspinwall was an important base of operations for them at that time), to a Messrs. McKesson & Robbins, Wholesale Druggists, New York City(a pretty great duplex!), New York, U.S.A.! The mail wasn't actually cancelled until the mail arrived in New York City on the 17th! It had likely been given to a ship captain to mail upon the arrival of his ship in New York City! Noted imperfections aside, this cover remains a unique, neat piece of Panamanian, Colombian, and U.S. postal history connected to Messrs. McKesson & Robbins, Wholesale Druggists!