Four hundred years. A vast geography. And an unfinished project to remake the world to match the desires of settler colonizers. How have settlers used violence and narrative to transform Turtle Island into what is currently called North America? What does that say about our social systems, and what happens next? Deploying analytical tools from diverse disciplines, and drawing on sources ranging from archives to pop culture and personal experience, Making and Breaking Settler Space addresses pressing questions left by the complex and obscured process of colonization. Adam Barker articulates a dynamic analytical model to explain how settler spaces have developed and continue to evolve. He traces the trajectory of settler colonialism, drawing out details of its operation from the imperial colonization of Turtle Island in the 1500s to contemporary contexts that include problematic activist practices by would-be settler allies. Making and Breaking Settler Space proposes an innovative, unified spatial theory of settler colonization in Canada and the United States. In the process, it uncovers systemic weaknesses that can inform the decolonization efforts of resurgent Indigenous nations and settler activists alike, and argues for relationships founded on solidarity and shared acknowledgment that the settler project is a failed one.