This is from a little known set of large circular cards included in USPS "Field Trip Through History" lesson plan kits that were issued for various decades in 1998. They were related to the stamps commemorating each decade of the 20th century issued by the post office in 1998.
Each decade kit contained 30 topic cards highlighting persons or events from that decade. The cards are about 6 inches across and are numbered on the back.
This great card will be shipped "bagged & boarded" and well packaged with stiff cardboard in the envelope.
Buyer pays $6.85 shipping.