For the first three centuries or so after the European discovery of the New World the principal source of immigrants to the two American continents and the Caribbean was not Europe but Africa. Only in the early nineteenth century did the accumulated total of European settlers in the New World exceed the approximately 10 million Africans who had made the trans-Atlantic voyage in the years since 1492. To explain the African diaspora by citing entrepreneurial instincts, the love of democracy, or the freely chosen decisions of migrants to follow the lodestar of American promise would be a mockery. Clearly, the involuntary movement of those 10 million Africans is best explained not in terms of their individual characters and choices but in terms of the catastrophically disruptive expansion of large-scale plantation agriculture and its accursed corollary, large-scale commercial slavery.
A comparable—though, to be sure, not identical—element of involuntariness characterized emigration from nineteenth-century Europe. Any generalization about what prompted a phenomenon as long-lived and complicated as the great European migration must, of course, be subject to many qualifications. All discussions of the migration process recognize both push and pull factors. But at bottom the evidence convincingly supports the argument that disruption is essential to the movement of people on such a scale. And, as in the African case, the best, most comprehensive explanation for a process that eventually put some 35 million people in motion is to be found in two convulsively disruptive developments that lay far beyond the control of individual Europeans. Those developments had their historical dynamic within the context of European, not American, history.
The first of these needs little elaboration. It was, quite simply, population growth. In the nineteenth century the population of Europe more than doubled, from some 200 million to more than 400 million, even after about 70 million people had left Europe altogether. (Only half of these, it should be noted, went to the United States—one among many clues that the American-magnet explanation is inadequate.) That population boom was the indispensable precondition for Europe to export people on the scale that it did. And the boom owed little to American stimulus; rather, it was a product of aspects of European historical evolution, especially improvements in diet, sanitation, and disease control.
The second development was more complex, but we know it by a familiar name: the Industrial Revolution. It includes the closely associated revolution in agricultural productivity. Wherever it occurred, the Industrial Revolution shook people loose from traditional ways of life. It made factory workers out of artisans and, even more dramatically, turned millions of rural farmers into urban wage-laborers. Most of those migrants from countryside to city, from agriculture to industry, remained within their country of origin, or at least within Europe. But in the early stages of industrialization the movement of people, like the investment of capital during the unbridled early days of industrialism, was often more than what the market could bear. In time most European societies reached a kind of equilibrium, absorbing their own workers into their own wage markets. But in the typical transitional phase some workers who had left artisanal or agricultural employments could not be reabsorbed domestically in European cities. They thus migrated overseas.
The large scholarly literature documenting this process might be summarized as follows: Imagine a map of Europe. Across this map a time line traces the evolution of the Industrial Revolution. From a point in the British Isles in the late eighteenth century the line crosses to the Low Countries and Germany in the early and mid nineteenth century and to eastern and southern Europe in the late nineteenth and early twentieth centuries. Across the same map a second line traces the chronological evolution of migration to the United States. As it happens, the two lines are almost precisely congruent—migration came principally from the British Isles in the eighteenth and early nineteenth centuries, then mainly from Germany, and finally from the great watersheds of the Vistula and the Danube and the mountain ranges of the Apennines and Carpathians to the south and east.
The congruence of those lines is not coincidental. Industrialization, in this view, is the root cause and the most powerful single variable explaining the timing, the scale, the geographic evolution, and the composition of the great European migration.
For another perspective on the importance of understanding the European migration from a European point of view, consider the lyrics of a nineteenth-century Italian folk song called "The Wives of the Americans." In this case, the "Americans" were men who had gone off to America and left their wives behind in Italy—specifically, the southern region of Campania. In fact, men, young men in particular, predominated in the nineteenth-century migratory stream, and their predominance constitutes a reliable indicator of their purposes. Many of them never intended to settle permanently elsewhere but hoped to work abroad for a time and eventually return to the old country. Repatriation rates for European immigrants averaged nearly 40 percent. Only the Jews and the Irish did not go home again in significant numbers. For some later, "new" immigrant groups, especially from the southern Danube regions, repatriation rates ran as high as 80 percent.
The song describes the wives of the Americans going to church and praying, "Send money, my husband. Send more money. The money you sent earlier I have already spent. I spent it on my lover. I spent it with pleasure. Send more money, you cornuto fottuto [damnable cuckold]." Those lyrics conjure an image of immigration quite different from the one General Patton urged on his Italian-American troops in 1943. Together with the figures on repatriation, they offer a strong corrective to uncritical reliance on the American-magnet explanation for the past century's European migration.