Have You Ever Seen a JFK Mourning Cover?

Have you ever seen a JFK mourning cover?  After President Kennedy was assassinated November 22, 1963, countless Americans sent letters of condolence to First Lady Jackie Kennedy.  Her private secretaries were tasked with hand-writing the return addresses and sending notes of appreciation to each person.  The envelope and note inside include the classic black border used to indicate a mourning cover.  Pretty interesting, right?!