Marge accompanies Bart, Lisa, and Milhouse to the Springfield Public Library, where they discover a dearth of reading material. Marge volunteers to help the children with their research papers, claming she knows more than a little about history. The first story features King Henry the Eighth (Homer) and his quest to have a male heir to the throne. His attempts at having a child with his current wife, Margarine of Aragon (Marge), have failed miserably. Henry takes an interest in Anne Boleyn, prompting Margarine to drag him to a marriage counselor (Dr. Hibbert). The marriage counselor encourages Homer to dump Margarine and “get busy.” Henry turns to Sir Thomas More (Ned Flanders) for help in getting a divorce. More tells Henry there’s no such thing as divorce in the Catholic church, so Henry decides to form his own religion. Henry then dumps Marge and marries Anne Boleyn. When Anne bears him a daughter, Henry has her beheaded. Henry then weds a succession of wives, including actress Jane Seymour and Skinner’s mother, all to no avail. Henry kills so many wives that Advisor Moe announces that the kingdom is running low on pikes for the heads. On his deathbed Henry asks Margarine to forgive him. Margarine responds by suffocating Henry with a pillow.

When Lisa is unable to find any books on Sacagawea, Marge begins another history lesson. The time is 1804, when President Jefferson dispatched Lewis (Lenny) and Clark (Carl) to find the Northwest Passage. Accompanying the pair on the journey is a band of explorers including Nelson, Jimbo, Kearney, and Otto. After paddling up the Mississippi from St. Lewis, the group camps for the winter. They seek help from a group of Native Americans, which is headed by Chief Homer. Homer offers the group the services of his daughter, Sacagawea (Lisa), who will help guide them on their journey. As the group travels through the countryside, Otto ignores Sacagawea’s advice and eats some poison berries. He dies. Fearing for the safety of the others, Sacagawea warns that if they encounter a mountain lion, everyone should try to make themselves look as big as possible. A year later the tired travelers encounter a Shoshone war party and are greatly outnumbered. Sacagawea recognizes her brother (Bart) among the braves. Sacagawea rushes forward and prevents a battle from occurring. Eventually the travelers reach the Columbia River. Lewis and Clark belittle Sacagawea, saying she needs to be more grateful to them for bringing civilization to her people. Furious at the lack of gratitude, Sacagawea trudges off, telling the others that they only completed the journey because of her help. Later a mountain lion advances on Sacagawea. Lewis and Clark run up, and remembering Sacagawea’s words, make themselves look bigger. The lion runs off. Sacagawea looks off in the distance and sees the Pacific Ocean. Lewis and Clark realize they’ve discovered the Northwest Passage.

When Bart expresses disinterest in writing a paper about someone boring, Marge proceeds to tell him the story about young prodigy Mozart (Bart) and his jealous sister Salieri (Lisa). As Salieri studies diligently at the piano, trying to better herself, Mozart sneaks up behind her and drops a plague rat down her dress. Salieri pulls out the rat and tosses it away. Salieri wonders why God gave such talent to such an undeserving fool. Later, at a concert hall, Viennese Rainier Wolfcastle announces the winner of a piano competition. Mozart wins and then charms the crowd. Salieri is furious. During the opening of Mozart’s “The Musical Fruit,” Salieri has an idea. She spikes Emperor Joseph II’s (Mr. Burns) wine with a sedative, causing him to fall asleep during the performance. The fops in the audience see the emperor sleeping and decide to follow suit. Soon the entire audience is asleep. Mozart sees this and — horrorstruck — stops conducting. Soon after, Mozart’s health takes a turn for the worse. On his deathbed Mozart tells Salieri that in the eyes of history, her music would be judged best. Now that he’s dying young, however, he’ll be cool forever. He then dies. Salieri finds a requiem that Mozart composed and places her own name on it. She brings it to the emperor, who has already discovered Mozart’s replacement: Beethoven. Back in the library, Lisa tells Marge the story sounds like Amadeus, which was historically inaccurate.