Mark Castillo

Dr. Mark Castillo is the Assistant Director of the University of Pennsylvania's International Relations Program, where he also lectures. He is a historian of American higher education and political history. His book, The Seedlings of Belonging: How Harvard Boys Learned the Politics that Broke the Nation Before the Civil War, is under contract with Fordham University Press for its series The North's Civil War.

The book returns to the college years of the men who sparked the Civil War to explain why generations educated to lead the republic proved so poorly prepared to preserve it. In doing so, it examines student self-government at Harvard from 1768 to 1854--a world with no adult in the room, where Northern and Southern boys came to join the same societies and swear the same oaths against the College. It draws on student diaries, disciplinary records, society rolls, family papers, newspapers, and the Civil War service of 1,576 Harvard alumni. From that evidence it shows how these students learned the politics of loyalty and exclusion. They consequently left Harvard knowing only how to compel assent, and they carried that skill into public life as the nation divided over slavery.

He teaches Research Methods and Practice in International Relations and the Senior Thesis Seminar, and he has advised the program's majors since 2012. He designed and taught Secret Intelligence and American Democracy, 1776 to Present. With Frank Plantan, the program's former co-director, he co-taught Introductory Theory and Practice of Counterintelligence, which The Daily Pennsylvanian listed among Penn's most in-demand courses. He has presented his research at meetings of the History of Education Society and the American Educational Research Association.