This chapter examines cross-border fugitive slave activities in continental North America (the United States, Canada, Florida, and Mexico) during the 19th century. It begins with examples of fugitive slaves crossing borders in search of individual liberation. The second section examines diplomatic responses to these fugitive escapees, especially the signing of international treaties to prevent fugitive escape. The third part focuses on the contributions of fugitive slaves to antislavery mobilization across borders. These organizing efforts in different nations and territories took place because such efforts were either illegal or difficult to accomplish within the existing boundaries of the nation-state. The fourth part examines the creation of fugitive settlements across borders, especially in northern Florida, central Canada, and northern Mexico. These black communities served as beacons of freedom to fugitives and were among the first postemancipation settlements on the North American continent. The major contextual point of this cross-national analysis is that territorial conflict provided a gateway to freedom for fugitives. The major objective of the chapter is to provide a cross-national examination of fugitive movements, laws, and communities in support of transnational history.