The civil rights and women's movements led to momentous changes in public policy and corporate practice that have made the United States the global paragon of equal opportunity. Yet diversity in the corporate hierarchy has increased incrementally. Lacking clear guidance from policymakers, personnel experts had devised their own arsenal of diversity programs. Firms implicated their own biased managers through diversity training and grievance systems and created a paper trail for personnel decisions, but they maintained the deeper structures that perpetuate inequality. Firms that changed systems for recruiting and developing workers, organizing work, and balancing work and life saw diversity increase up the hierarchy, but those firms are all too rare. The courts and federal agencies have found management processes that do not explicitly discriminate to be plausibly unbiased, and they rarely require systemic reforms. Our elaborate corporate diversity programs and public regulatory systems have largely failed to open opportunity, but social science research points to a path forward.