The Founders' Party and Heritage Display is an event held at the end of September, at the Lockwood Mansion. The First Founders' Party was held on September 24, 1864. The most recent one happened in 2009.
Founding Families organized it to display the heritage of people the founders in Mystic Falls. At the 2009 Founders' Party and Heritage Display, the Founders' Council were counting on Elena to bring the Gilbert Compass so they could use it to track vampires, but they were unable to get it that night, as Elena allowed Jeremy to keep it because Grayson said it belonged to him.
Elena attended the party because the Gilbert family's founding heritage was very important to her parents, and she went with Stefan as her date. Damon compelled Caroline to take him to the party as her date, despite her fear of what her mother would say. He also compelled her to wear a specific dress. His reasoning for wanting to attend the party was to reclaim the Bennett Talisman that he had hid over a century prior. Stefan, who wanted a way to get an upper hand on Damon, danced with Caroline and used the opportunity to spike her champagne with vervain.
There was a registry on display of the first Founders' Party in 1864. Elena read the names aloud and realized that Damon and Stefan's names were on it, since they were at the first party. Since Elena didn't know that they are vampires who have been alive since before 1864, they lied and said that they were their ancestors after whom they were named.
During this event, Bonnie lit a candle with her powers. She's shocked at her abilities, and later tried again in the Lockwood's dining room, but it didn't work. Defeated, she heads to another room, but passes a lit candle on the wall by the doorway before turning around and seeing that all of the candles in the room have lit themselves.
Elena was in the bathroom freshening up with Caroline when she noticed a healing wound on Caroline's neck underneath her scarf. Caroline told her to stop, but Elena saw more scars on her back and shoulderblades. Caroline runs off, and Elena runs off to tell Stefan what has happened. Caroline runs into Damon and tells him that Elena saw her bite marks, but that she didn't tell her anything about how she got them. Damon was angry at first, but then started to be nicer to her before biting her neck and drinking her blood deeply. Since Stefan had slipped her vervain, Damon became weakened by her blood, which gave Stefan the opportunity to take him home and lock him in the basement cellar of the Salvatore Boarding House.