This study presents initial findings of a new ongoing research project aimed to identify important predictors and mechanisms of exceptional human longevity. For this purpose the detailed data on long-lived people surviving to 100 years in the Unites States are collected, validated, and analyzed. The study found that being born to a young mother is an important predictor of person's longevity. The study also found that the "stout" body build at age 30 years (being in the heaviest 15% of population) significantly decreases chances of survival to 100 years. These findings demonstrate that early-life and mid-life personal characteristics play an important role in human longevity.