Breaking the rules
Despite having very strict time travel rules, ‘Quantum Leap’ has broken them on a number of occasions.
The main rule is that Sam Beckett could only leap into the bodies of people who had lived during his lifetime, meaning the writers could go back as far as 1953 - the year the hero was born.
However, Sam was sent back to 1862, and leapt into the body of an American Civil War soldier, with the explanation being the man was genetically similar to his great-grandfather.