The Great Migration-the early twentieth-century migration of millions of African Americans
out of the South to locations with better social and economic opportunities-is understood to be
a key element in the progress of African Americans in the U.S. This paper evaluates the role of
the Great Migration on an essential dimension of lifetime wellbeing-longevity. Using data on
precise place of birth, place of death, and age at death for individuals born in the Deep South in
the early twentieth century, we seek to identify the impact of migration on mortality among older
African Americans. To sort out causal effects we rely on the fact that proximity of birthplace to
early twentieth century railroad lines had a powerful effect on migration, and thus serves as a
viable instrument for migration. We find that there was positive selection into migration, in
terms of human capital and physical health. Estimates indicate that migration reduced longevity,
perhaps because of relatively poor health conditions in the urban areas to which this population
migrated.