His research and teaching focuses on transatlantic migration, labor, and radicalism. He is the author of Immigrants against the State: Yiddish and Italian Anarchism in America (University of Illinois, 2015), coauthor (with Mario Gianfrate) of Michele Centrone, tra vecchio e nuovo mondo: Anarchici Pugliesi in difesa della libertá spagnola (SUMA Editore, 2012) and co-editor (with Patryk Babiracki) of Cold War Crossings: International Travel and Exchange in the Soviet Bloc, 1940s-1960s (Texas A&M Press, 2014) and (with Peter Cole and David Struthers) Wobblies of the World: Towards a Global History of the IWW (Pluto Press, forthcoming 2017).