This is a Colorano Silk Maximum Card with the "Legend of Sleepy Hollow" stamp that was issued on October 10, 1974. The stamp features a scene from Washington Irving's "The Legend of Sleepy Hollow" in which the infamous Headless Horseman pursues Ichabod Crane. The story was first published in 1820. Wikipedia has a summary here.
This is a post for Sunday Stamps at Viridian's Postcard Blog