This paper studies the long-run mortality effects of in-utero and early-life economic conditions. We examine how local economic conditions experienced during the Great Depression, proxied by county-level banking deposits during in-utero and first years of life, influence old-age longevity. We find that a one-standard-deviation rise in per capita bank deposits is associated with an approximately 1.7 month increase in males' longevity at old age. Additional analyses comparing state-level versus county-level economic measures provide insight on the importance of controlling for local-level confounders and exploiting more granular measures when exploring the relationship between early-life conditions and later-life mortality.