To scholarship on contemporary Europe, this business history of European political economy challenges the linear teleology of European integration and reinforces its historical contingency in four ways. First, my narrative provincializes the Single Market by framing market integration as part of a long historical process, inflected by global events and affected by global actors like multinationals. Second, a focus on firms pluralizes the actors involved in market integration, expanding the scope of agency from nation states and supranational institutions to interest associations, companies, and even individual executives. Third, granular analyses of a wide range of firms problematize business influence on the market by uncovering instances in which business interests eclipsed those of the demos and by demonstrating the broad spectrum of firm perspectives on regional market integration – from active proponents to “business Eurosceptics." Fourth, engagement with arguments about the market’s winners and losers and the need for reform politicizes the history of market integration and situates this book among present debates about the future of regulating and doing business in Europe.