 Alpha Delta ( " AD " ) was initially founded by members of the Gamma Sigma Society . In 1847 , the society became the Dartmouth chapter of Alpha Delta Phi , a national fraternity . The house dissociated from its parent corporation in 1969 and renamed itself The Alpha Delta Fraternity . Alpha Delta is well known for being part of the inspiration behind the movie National Lampoon 's Animal House . The screenplay , co @-@ written by Chris Miller , class of 1963 , was inspired by a pair of short stories Miller wrote in National Lampoon in 1974 and 1975 ( " The Night of the Seven Fires " and " Pinto 's First Lay " ) about his experiences as a member of Alpha Delta . In November 2006 , Miller published a 336 page memoir of his experiences in the fraternity under the title The Real Animal House : The Awesomely <unk> Saga of the Fraternity That Inspired the Movie . Alpha Delta was derecognized by Dartmouth College on April 13 , 2015 . 
