The original Samantha apparently died at some point in the years following her abduction in 1973, but her DNA was still used for hybridization experiments. Agent Fox Mulder often thought he had finally found his sister when he would meet one of them until he realized they were clones.
Samantha Series' role in the colonization projectEditClones from an adult Samantha series worked as scientists in an abortion clinic in Rockville, Maryland, using the aborted fetuses for hybridization experiments (TXF: "Colony"). One of these hybrids posed as the authentic Samantha Mulder, seeking protection from the Mulder family, knowing her series was threatened; the women were all killed by an alien bounty hunter shortly after (TXF: End Game).
Another younger Samantha series worked on the Syndicate's plantations as part of an agrarian workforce in Alberta, Canada (TXF: "Herrenvolk"). Finally, one clone created for an unknown purpose posed as the authentic Samantha again in 1997 and was used by the Cigarette-Smoking Man in an attempt to coax Fox Mulder into quitting the FBI and work for him instead (TXF: "Redux II").