Elvis Presley's first national television appearance occurred on January 28, 1956, on CBS's Stage Show, hosted by the Dorsey Brothers. For this debut, the 21-year-old performed a medley of "Shake, Rattle and Roll" and "Flip, Flop and Fly," introducing his unique style to a national audience for the first time. Credit: CBS, Jackie Gleason Productions | History In Pictures

In November 1961, Enos became the first chimpanzee and the third hominid to orbit the Earth as part of the NASA Mercury-Atlas 5 mission. His successful two-orbit flight and safe recovery demonstrated that the spacecraft was ready for human passengers, paving the way for John Glenn’s historic flight months later. Credits: NASA, National Archives and Records Administration (NARA), Universal Newsreels | History In Pictures

Jim Varney provided the iconic southern drawl for Slinky Dog in the first two installments of the Toy Story franchise. After Varney passed away in 2000, his close friend Blake Clark took over the voice role for the subsequent films. Credit: Walt Disney Pictures | History In Pictures

A Warner Bros.-First National Picture (1946)