His research and teaching focus on urban, political, labor, and African American history in the twentieth century. He is the author of Philadelphia Divided: Race and Politics in the City of Brotherly Love (University of North Carolina Press, 2007) as well as numerous articles and reviews. He has received fellowships and grants from the Organization of American Historians, American Philosophical Society, and the Newberry Library. He is currently working on an urban and labor history of public transportation in Philadelphia from the 1880s to the 1960s tentatively titled "Capital’s Quest: Management, Labor, and the Search for Social Control in Philadelphia’s Mass Transit Industry."