Answer:
Since the beginning of humanity, the human being has been a migrant species, starting from the first hunting cultures, through agricultural settlements, industrialized society, etc., geographical mobility has been part of the history of peoples. Human beings have always looked for ways to improve their living conditions, driven to migrate.
Step-by-step explanation:
During the nineteenth century, the expansion of the economy had two important migratory flows, from the side, from the metropolis to the colonies or areas of influence of European countries, such as Latin America, Oceania and Africa as destinations; on the other hand, the North American economic center attracted numerous mainly European labor. Transoceanic migration became the economic dynamic of the metropolis, so that it was maximum until the twenties of the twentieth century and descended because of the Great Depression.
After World War II, the boom in central and northern Western Europe included several million migrants from countries such as Portugal, Spain, Italy, Yugoslavia, Greece, Turkey, seeking better employment in the most important sectors of industrialization, the economic crisis of the second half of the seventies meant the return of many migrants, thus reducing the foreign presence belonging to European countries.
Speaking of approximate figures one could guess during the nineteenth century until the Depression of the thirties of the twentieth century emigrated more than 60 million Europeans.