While the European Union (EU) was founded on the concept of equality as a fundamental value in 1993, the United States was created at a time when women were considered legally inferior to men. This has had the lasting effect of preventing women in the United States from making inroads into positions of power. While legislated board gender diversity (BGD) mandates have been instituted in some EU countries, the United States has been loath to take that route, relying instead on the goodwill of corporate boards, with little progress. On September 30, 2018, however, California enacted a law that has stirred much controversy for requiring at least one woman to be on the boards of corporations headquartered in the state by 2020. Based on our analysis, the California bill and other similar legislative efforts will fail without parallel constitutional action and cultural change in the United States. We begin by examining the individual, institutional, and cultural reasons why the United States lags so far behind the rest of the industrialized world. We then discuss recent activism by powerful institutions such as Nasdaq and Goldman Sachs that may signify broader cultural change and receptiveness to positive action. Next, we conduct an analysis of the legislative, cultural, and constitutional factors that have helped the EU succeed in increasing board diversity. We conclude by offering a normative solution that can pave the way to achieving gender equality in the United States. Learning from the EU model, the United States must let go of the Equal Rights Amendment and adopt a Substantive Equality Amendment to the Constitution requiring positive action to facilitate laws enabling gender equality. This solution will have broad cultural impact outside of the board context and will help change the lived experiences and outcomes for women in the United States for generations to come. It will change the course of history.