In spite of the many historical studies of Irish Protestant migration to America in the eighteenth century, there is a noted lack of study in the transatlantic migration of Irish Protestants in the nineteenth century. The main hindrance in rectifying this gap has been finding a method with which to approach a very difficult historiographical problem. The Invisible Irish endeavours to fill this blank spot in the historical record. Rankin Sherling imaginatively uses the various bits of available data to sketch the first outline of the shape of Irish Presbyterian migration to America in the nineteenth century. Using the migration of Irish Presbyterian ministers as "tracers" of a larger migration, Sherling demonstrates that eighteenth-century migration of Protestants reveals much about the completely unknown nineteenth-century migration. An original and creative blueprint of Irish Presbyterian migration in the nineteenth century, The Invisible Irish calls into question many of the assumptions that the history of Irish migration to America is built upon.