Between 1870 and 1945, advances in communication and transportation simultaneously expanded and shrank the world. New technologies erased distance and accelerated the global exchange of people, products, and ideas on an unprecedented scale. A World Connecting focuses on an era when growing global interconnectedness inspired new ambitions but also stoked anxieties and rivalries that would erupt in two world wars—the most destructive conflicts in human history. In five interpretive essays, distinguished historians Emily S. Rosenberg, Charles S. Maier, Tony Ballantyne, Antoinette Burton, Dirk Hoerder, Steven C. Topik, and Allen Wells illuminate the tensions that emerged from intensifying interconnectedness and attempts to control and shape the effects of sweeping change. Each essay provides an overview of a particular theme: modern state-building; imperial encounters; migration; commodity chains; and transnational social and cultural networks. With the emergence of modern statehood and the fluctuating fate of empires came efforts to define and police territorial borders. As people, products, capital, technologies, and affiliations flowed across uneasily bounded spaces, the world both came together and fell apart in unexpected, often horrifying, and sometimes liberating ways. A World Connecting goes beyond nations, empires, and world wars to capture the era’s defining feature: the profound and disruptive shift toward an ever more rapidly integrating world.