After Execution (1960), this is the second episode of The Twilight Zone (1959) involving time travel in which Russell Johnson (Peter Corrigan) appears.
Pete Corrigan mentions HG Wells in relation to his story The Time Machine, which had also just been made into a movie the year before this episode (1960).
This episode, which concerns the assassination of Abraham Lincoln, originally aired on January 13, 1961, only one week before the inauguration of U.S. President John F. Kennedy. The assassination of JFK later had a direct impact on The Twilight Zone (1959) as Night Call (1964), which was to have aired on November 22, 1963, was rescheduled for February 7, 1964. It also served as the basis of Profile in Silver/Button, Button (1986).
This episode takes place on April 14, 1961 and April 14, 1865.