Chronologically speaking, September 20, 1862 is the earliest leap date in the series' history. It is Sam's only leap to take place outside of the 20th Century.
The title refers to another name for the American Civil War: "The War Between the States".
After The Leap Back - June 15, 1945 (1991), this is the second and final time that Sam leaps outside of his own lifetime.
This is Michael D. Robert's (Isaac King) second appearance in the series. He first appeared in season 1, The Color of Truth - August 8, 1955 (1989) which also involved a storyline that dealt with racial issues.
Sam's leaping into his great-grandfather, John Beckett, in 1862 technically makes John history's first time traveler (as he leapt forward to Sam's time).