The GCS aimed to initiate and build a multi- and inter-disciplinary model of healthy ageing among community-dwelling individuals and those residing in care facilities who lived to extreme old age. Participants were from Georgia, United States of America. In phase 1, participants included 91 individuals aged 60 years, 93 individuals aged 80 years, and 137 centenarians who completed baseline assessment from 1988 to 1992. Phase 2 was a 5-year longitudinal follow-up of the same participants tested in phase 1 from 1992 to 1997. In phase 3, a new cohort of almost 250 centenarians and 80 octogenarians was recruited and completed baseline assessment from 2001 to 2003. Some of these participants completed a neuropathology follow-up and donated their brains for post-mortem examination.