The Council of Philatelic Organizations (COPO) seems to have existed for a brief period of time, but expired due to lack of funding.
National Stamp Collecting Month continues, though it seems to have been scaled down with fewer events scheduled and a limited number of special cancels. One wonders why there has never been a stamp issued by the USPS to note it.
A recent statement by the USPS says that "National Stamp Collecting Month is an annual event that was created by Postal Service officials and members of the Council of Philatelic Organizations to entice children to become stamp collectors. It also serves as a source of camaraderie for philatelists who enjoy a hobby that connects generations of collectors, including some famous figures."
Some of the famous collectors the USPS cites include President Franklin Roosevelt, Charlie Chaplin, John Lennon, Ayn Rand and Amelia Earhart.
The cover illustrated here is from the very first National Stamp Collecting Month in 1981 and was issued by COPO. If any readers have later COPO covers, it would be great if you'd post images of them in the About.com Stamps forum.
(Illustrated cover from the collection of the author.)