Why did 60 million people leave Europe for overseas destinations in the hundred years after the Napoleonic Wars? 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 in the years between 1815 and 1930. Written specifically for undergraduate students, it reviews the current literature in several European languages, summarises both economic and demographic theories, and analyses the relation between economic change in Europe and the emigration rate, as well as discussing the economic effects of immigration on the receiving countries and the social experiences or the immigrants.