HANDLS participants are a fixed cohort of 3,722 community-dwelling African American and white adults aged 30-64. Participants were recruited from 12 pre-determined neighborhoods (groups of contiguous census tracts) comprising an area probability sample of Baltimore City (map) and one dress rehearsal site in South Baltimore. The area probability sample was designed to sample a wide range of socioeconomic and income circumstances in a 4-way factorial cross of age (seven five-year age bands between 30-64), sex, race, and socioeconomic status indexed by poverty status (below or above 125% of the Federal Poverty Guidelines). HANDLS is planned as a 20-year longitudinal study. Using our mobile research vehicles, we plan to re-visit each neighborhood for three months every three years.