His research and teaching focuses on the twentieth-century United States, with a particular interest in the history of capitalism, social movements, popular culture, and media. As a public and digital historian, Joshua works actively to increase access to history outside the classroom.His forthcoming book, From Head Shops to Whole Foods: Activist Entrepreneurs since the 1960s (Columbia, 2017) examines how a range of small businesses--including natural foods stores, head shops, feminist businesses, and African American booksellers--emerged out of social movements and countercultures in the 1960s and '70s. These businesses sought to remake American capitalism, to advance their movements' political goals, and to create new forms of public space.