Franklin is the only historical figure encountered by the time-travelers during their journeys throughout history. The only other figure depicted in the series is Caligula, but neither the Browns nor Marty actually meet the future Roman emperor.
In the episode, "Go Fly A Kite", Verne Brown (mistakenly) claims that he is Franklin's son, and attempts to take up residence, particularly after being told to "Go home!!". Franklin actually did acknowledge fathering a child (William Franklin) out of wedlock. In 1752, Franklin's only daughter, Sarah, was 9 years old, a year older than Verne's age in the series.