Professor Richardson teaches nineteenth-century American history at both the undergraduate and the graduate level. Her early work focused on the transformation of political ideology from the Civil War to the presidency of Theodore Roosevelt. It examined issues of race, economics, westward expansion, and the construction of the concept of an American middle class. Her history of the Republican Party, To Make Men Free (2014) examines the fundamental tensions in American politics from the time of the Northwest Ordinance to the present. She is currently working on an intellectual history of American politics and a graphic treatment of the Reconstruction Era.