We leverage the introduction of antibiotics in 1937 to demonstrate the long-run impacts
of pneumonia in infancy on human capital and socioeconomic status among American adults. These
impacts are larger for whites, despite the fact that blacks experienced larger post-1937 declines in
pneumonia mortality rates. We argue that pre-Civil Rights barriers inhibited blacks from
consolidating the socioeconomic returns to improved health endowments by depressing returns to
human capital accumulation and limiting complementary investments. Consistent with this, we
demonstrate gradients in impacts for blacks (but not whites) by indicators of institutional
segregation. Our results highlight the importance of responsive investments in translating early-life
health into later life socioeconomic status and persistent impacts of racial segregation.