Hagen’s research focuses on frontiers and borderlands, race and indigenous people, labor and migration, the built and natural environments, resources and settler colonialism. She is especially interested in questions of space, power, violence, law and the state. Through her academic and public history work, she approaches these broad themes from many directions. Based on research in primary sources ranging from archival documents to architectural resources, her work ranges from theoretical analyses of international structural developments to contextualized micro-histories of single historic sites.
Northern Plains Borders and the People in Between, 1860 - 1940