This attractive, large, "Due-3" cover was sent from the Army and Navy Pension Office, Brooklyn, New York, to Newburgh, New York, on March 7, (1870s)! It was addressed to an Elizabeth King.   

To continue, the deep green, 3-Cent, U.S., "Washington," is in very fine condition! The black, fancy cancel from the Old Brooklyn P.O. is immaculate! The CDS from the Brooklyn Post Office is pretty good, too! The, "DUE 3," auxiliary marking was well applied! The additional postage was likely required due to the larger size of the envelope.

Lastly, as for the envelope itself, it's in pretty good condition. Outside of the customary, ink stains that are often found on these types of postal history, there are some minor stains on either side. There are two, small tears in the top due to how the envelope was opened so long ago. The envelope was opened at the left side, and has been reduced a bit there. The right side is a bit open, too. While there are those two, aforementioned tears, the back flap is 95% complete! Relatively minor blemishes aside, this is a neat piece of U.S. military postal history connected to the Army and Navy Pension Office in Brooklyn, and Elizabeth King, most likely the wife or mother of an American veteran!