Birth in the U.S. Plantation South and Racial Differences in all-cause mortality in later life

The American South has been characterized as a Stroke Belt due to high cardiovascular mortality. We examine whether mortality rates and race differences in rates reflect birthplace exposure to Jim Crow-era inequalities associated with the Plantation South. The plantation mode of agricultural production was widespread through the 1950s when older adults of today, if exposed, were children. We use proportional hazards models to estimate all-cause mortality in Non-Hispanic Black and White birth cohorts (1920-1954) in a sample (N = 21,941) drawn from REasons for Geographic and Racial Differences in Stroke (REGARDS), a national study designed to investigate Stroke Belt risk. We link REGARDS data to two U.S. Plantation Censuses (1916, 1948) to develop county-level measures that capture the geographic overlap between the Stroke Belt, two subregions of the Plantation South, and a non-Plantation South subregion. Additionally, we examine the life course timing of geographic exposure: at birth, adulthood (survey enrollment baseline), neither, or both portions of life. We find mortality hazard rates higher for Black compared to White participants, regardless of birthplace, and for the southern-born compared to those not southern-born, regardless of race. Race-specific models adjusting for adult Stroke Belt residence find birthplace-mortality associations fully attenuated among White-except in one of two Plantation South subregions-but not among Black participants. Mortality hazard rates are highest among Black and White participants born in this one Plantation South subregion. The Black-White mortality differential is largest in this birthplace subregion as well. In this subregion, the legacy of pre-Civil War plantation production under enslavement was followed by high-productivity plantation farming under the southern Sharecropping System.