Gramps can be asked about the 'pre-holocaust days', and so it seems that he has lived in Miami for most of his life, even before the war. He is old enough to remember when the Bahia Mafia ruled Miami, and he comments that they were wiped out by the Change. When prompted about joining the party earlier in the game, he will mention that he used to travel more in his youth. It is unknown exactly how he survived the war.
He was married to a woman who loved to work with kevlar, and is now widowed. He doesn't get along with his son, but apparently keeps him around to do repair work.
He plays a key role in Fountain of Dreams, giving the player quests. Towards the end of the game, he joins the party to challenge the Killer Klowns for control of the Fountain of Youth. At the end of the game, upon beating the Klowns, Gramps admires the beauty of the Fountain, commenting that 'humanity has hope yet'.