Why did sixty million people leave Europe for overseas destinations between 1815 and 1930? What were the social and economic causes and effects of this mass migration? Why did some people emigrate and not others, and why did so many emigrants return to Europe? This short, comprehensive survey answers these and other questions regarding emigration from different parts of Europe. Written specifically for undergraduate students, it reviews the current literature in several European languages, summarizes both economic and demographic theories, and analyzes the relation between economic change in Europe and the emigration rate.