Lisa goes to the Lincoln Memorial to ask advice from Abe Lincoln, but tons of tourists are there asking him for advice so he can't get his say in. So he then goes to the Jefferson Memorial, and she's the only person there.
Lisa: "President Jefferson, I have a problem..."
Jefferson: "Yes, the Lincoln Memorial was full!"
Mocking how everyone who visits DC goes to the Lincoln Memorial, but not the Jefferson.
Episode: When Lisa is a finalist in an essay competition in Washington, DC