"A History Channel Thanksgiving" is the thirteenth episode of Season Fifteen, and the 222nd overall episode of South Park. It aired on November 9, 2011.
After watching a Thanksgiving special on The History Channel, the boys believe that aliens were involved in the original feast. But, questions remain... was the first Thanksgiving haunted? Is alien technology responsible for stuffing? The truth could change Thanksgiving for everyone.
After a lecture from 1/16th Cherokee Indian, David "Running Horse" Sawitzky, the boys are assigned to write a report on the history of Thanksgiving. They view a TV show on The History Channel that suggests the first Thanksgiving in 1621 was influenced by the presence of extraterrestrials. Despite Kyle Broflovski's outrage at the program's arguments, he is outvoted when the other three boys decide nonetheless to use the program as a source in their report. After turning in their reports, agents from the History Channel show up and demand the boys tell them where they got their information from. When the boys explain they derived their knowledge from that program, the head agent sees this "coincidence" as validation of History's theories, and shows the boys' testimonials on a subsequent program, crediting Stan Marsh as a "History Expert", and Kyle as a "Professor of Thanksgiving - DeVry Institute", despite the fact that Kyle is shown arguing against the idea. This incurs the wrath of Sawitzky, who shows up at Kyle's house and holds him, Stan and Kenny at gunpoint.
Captain Miles Standish of Plymouth, a planet in Canis Major whose inhabitants resemble colonial era American Pilgrims, falls to Earth. On Plymouth, the Pilgrim leader rallies his people, saying that their enemies, the Indians, have raided their stuffing mines, which causes a stuffing shortage on Earth that causes Cartman to panic. The captain shows up at Kyle's house, kills Sawitzky, and asks Kyle for help returning to his planet. After Natalie Portman drives them to a wooded area, Standish shows Kyle a map of five planets: Earth, Plymouth, Indi, Colthenheim and Green Lantern World, which are connected by wormholes that on the map, resemble the hand-traced drawings of turkeys made by schoolchildren. Standish explains that his people and their enemies were indeed responsible for the first Thanksgiving, and warns Kyle that because the 300-year treaty between Plymouth and Indi has ended, the Indians will plunder the Plymouth stuffing mines. Agents from the History Channel appear, and when they tell Standish that they failed to open the wormhole to Plymouth by drawing the turkey symbol at Plymouth Rock, Standish informs them that they need Natalie Portman, who is the Keeper of the Portal. After being wined and dined by Kyle, Portman "opens her wormhole", sending Standish back to Plymouth, where he defeats the Indians.
Back on Earth, Standish's campaign against the Indians is related in another History TV special, which also adds the new theory that the first Thanksgiving was haunted, much to Kyle's outrage.