The listing, USA #1591 9¢ shiny gum, Right of People Peacably to Assemble, mint has ended.
USA Stamp commemorating the Right of People Peacably to Assemble
Year: 1977
Catalog # 1591 shiny gum
Note: this is the shiny gum version
I have several of these stamps, the scan is representative of what you will receive.
My general terms for stamp-related Listia lots can be found here (please read, it answers a lot of basic questions):
http://listiarules.webs.com/