This volume examines how the failure of the potato crop in the late 1840s led to the mass exodus of 2.1 million people between 1845 and 1855. They left for destinations as close as Britain and as far as the United States, Canada and Australia, and heralded an era of mass migration which saw another 4.5 million leave for foreign destinations over the next half-century. How they left, how they settled in the host countries and their experiences with the local populations are as wide and varied as the numbers who left and, using extensive primary sources, this volume analyses and assesses this in the context of the emigrants themselves and in the new countries they moved.