A New Identity : the Costs and Benefits of Diversity in Civil War Combat Units for Black Slaves

JEL Classification: J24, M12, Z13 We examine the role of peers, commanders, and travel on the later life outcomes of black slaves and freemen who fought in the Union Army. Because most of the black soldiers who served were illiterate farm workers, the war exposed them to a much broader world. In this sense, the Union Army can be viewed as a training program with heterogeneous treatment effects. In the short-run the combat unit benefited from company homogeneity as this social capital minimized shirking, but in the long-run men’s human capital and information was best served by fighting in heterogeneous companies. Dora L. Costa MIT Department of Economics, E52-274C 50 Memorial Drive Cambridge, MA 02142 and NBER [email protected] Matthew E. Kahn The Fletcher School Tufts University Medford, MA 02155 [email protected]