Costanza Biavaschi, from the Norwegian University of Science and Technology, explores the link between restrictions to the electoral franchise enacted in the progressive era and voting behaviour of U.S. Representatives on immigration policy. They put particular attention on exploring the role played by naturalized U.S. citizens in explaining congressional support for restrictive immigration policy measures. To this end, they construct a unique dataset combining roll call votes on immigration policy cast between 1897 and 1924, with a wealth of congressional district level economic and demographic characteristics.