What year did Duke Ellington win the Pulitzer Prize?

The Pulitzer Jury recommended Edward Kennedy "Duke" Ellington for a Pulitzer Prize for Music in 1965, but the Board rejected their suggestion. Ellington won a posthumous Special Citation (not a Pulitzer Prize) in 1999 "in recognition of his musical genius, which evoked aesthetically the principles of democracy through the medium of jazz and thus made an indelible contribution to art and culture."