This paper estimates the returns to human capital accumulation during the first era of mega-firms in the United States by linking employees at General Electric—a canonical enterprise associated with the “visible hand” of managerial hierarchies—to the 1940 census. I find large returns to higher education through seniority in the hierarchy, span of control, earnings, and selection into management training, using the proximity of land-grant colleges and historical universities to birth states for identification. The findings highlight the human capital determinants of the managerial revolution at a prominent firm, driven by earlier public investments in the U.S. education system.