Originally Posted by psylockolussus
They didn't exist or they weren't active sometime between 70s and DOFP.
Ok they were created in 1973
is from either 1981
So they did
exist publicly from 1985 at the latest and they were in still in production for several countries up until 1996
(which does not mean they were no longer in service after that point either).
You really are ignoring that viral site, it's timeline for Trask's work on mutant genetics, his Sentinels, the works.
Thats why they weren't mentioned in the original trilogy.
The most likely explanation will either be that something else has changed history to enable the Sentinel program to exist in the first place, or they were conveniently taken out of service just before all of the OT events (which would not explain why Stryker had none stationed at 3 mile Island, where he was keeping a load of dangerous mutants in cages...).