Plastino's "greatest pride"' was a story he drew for "Superman" #168 (April 1964, scheduled for publication Feb. 1964), titled "Superman's Mission for President Kennedy." The piece was done in collaboration with the Kennedy administration to help promote the president's national physical fitness program. In the story, Superman visits the White House, and trusts President John F. Kennedy with his secret identity. The story was produced shortly before Kennedy was assassinated, which led to the cancellation of its publication. At the behest of President Lyndon B. Johnson, it was published two months later, in "Superman" #170 (June 1964), with Plastino adding a title page showing a ghostly figure of Kennedy looking down from the heavens at Superman flying over Washington, D.C. Plastino had always believed the artwork had been donated to the John F. Kennedy Presidential Library and Museum in Boston, but the artwork was placed on auction by a private entity in late 2013. DC Entertainment subsequently purchased the art and donated it to the Library.