The beginning of the club started after Emma left the Lost Motorcycle Club in Los Santos. She left due to the fact that the Lost in Los Santos were being hunted down by an unknown assailant who was responsible for the death of Johnny Klebitz. Emma however left the Lost, however she was marked for death by her former president. She went into hiding for a brief period, however when members of her former club found her, they ended up dead. With the Lost now loosening their mark for death on Emma, she began creating her own motorcycle club, known as the Vespucci Angels.
The Vespucci Angels live somewhere on Vespucci Beach, obviously which implies where they got their name. As far as their operations are concerned however, the Angels are known to be into any form of criminal activity, ranging from forgery and counterfeit money, to even the production and distribution of drugs.