Jonathan is the author of Freedom Soldiers and Valiant Men of War, histories examining the military experiences of Black soldiers and their families during the US Civil War.

He earned his Ph.D. at Brown University and teaches at Purdue University. Before joining Purdue, he was the Brown University-Tougaloo College Exchange Faculty Fellow and the Schwartz Postdoctoral Fellow at New-York Historical Society and the New School.

He is the recipient of awards including the Allan Nevins Prize and the Brown University’s Presidential Award for Excellence in Teaching.

He has published peer-reviewed articles in venues such as the Journal of American History and the Journal of African American History. His work has also appeared in the Washington Post and Time Magazine. He has been a research fellow at, among other institutions, the Houghton Library at Harvard University and the Gilder Lehrman Center for the Study of Slavery, Resistance, and Abolition of Yale University.

He has spoken at meetings of professional organizations, including the American Historical Association and Organization of American Historians, and appeared in the Emmy-nominated documentary about the commemoration of Black Civil War soldiers.