While writing a paper on an ancestor in her family who wasn't a total embarrassment, Lisa discovers a diary written by one of her father's ancestors, detailing how she took in a black slave named Virgil (who looks like Homer if he was black, or [[WesternAnimation/TheClevelandShow Cleveland Brown]] if he were drawn ''Simpsons''-style), but Milhouse also finds a diary from ''his'' ancestors, who have a different take on how Virgil was treated by the Simpson family.
* ExactWords: After witnessing Eliza Simpson backing off when her father told Colonel Burns where Virgil was hidden, Milford Van Houten said he couldn't look her in the eye again. The next day, he lost his sight after drinking tainted water. A vídeo of Eliza in an old age shows she married Milford.
* GenerationXerox: Monty Burns looks like Col. Burns used to during Virgil's tale, and the Simpson ancestors are depicted as looking exactly like their modern-day counterparts, albeit with different hairstyles. (Mabel even looks exactly like Marge, despite being Homer's ancestor, not Marge's. Perhaps the Simpson men all have a type.)
* GeniusBonus: Like [[spoiler: his descendant]] Homer, Virgil shares his name with a classical epic poet.
* IGaveMyWord: Hiram Simpson told about his oath to make Col. Burns stop trying to beat Virgil's whereabouts out of him. Col. Burns then decided to bribe Hiram.
* SeriesContinuityError: The Simpsons didn't arrive in America until the early 1900s when Abe was a child, as seen in [[Recap/TheSimpsonsS7E23MuchApuAboutNothing "Much Apu About Nothing"]] (although Abe's ancestors ''are'' shown living in Canada at the end of the episode, not the U.S.)
** Also, Lisa should have known that not everyone on Homer's side of the family is an idiot, a criminal, a freak, a sexual deviant, or a failure, as seen in [[Recap/TheSimpsonsS9E17LisaTheSimpsons "Lisa the Simpson,"]] when she learns that all the women on Homer's side of the family (save for Homer's half-brother, Herb, who, despite going broke twice, was a fairly successful businessman) are smart, emotionally mature, and are in high-paying, respectable careers. And why didn't she think to look into Marge's side of the family for good family members, or Mona's side of the family before she married Abe?
* UndergroundRailroad: Or, as Bart believes it should be called, "Aboveground Normalroad"