Repeat crossings of the North Atlantic by European migrants during the late nineteenth and early twentieth centuries were more frequent, faster-growing and had more intricate and significant impacts on the overall long-distance relocation process than previous scholarship has appreciated. This result is revealed by the first comprehensive accounting of all crossings between Europe and North America during the period, and by a consistent, broad, and process-based definition of migration which encompasses all transoceanic journeys except those made by tourists and business travellers. The rise of repeat migration between Europe and the United States was a rational response of migrant networks to the growth of “floating” job opportunities in America, and to the need for diversifying the risks of remote and uncertain employment across multiple individuals making multiple moves.

Early twentieth century migration across the North Atlantic was a human drama, a major international demographic shift, and a massive historical experiment in ethnic transformation during a period of unprecedented globalization. It was also a far-reaching multinational business containing both risks and rewards for its three fundamental participants: the movers, the moved, and the sovereign authorities on either side of the borders being traversed. Prior studies have not adequately explained this business or appreciated its significance.

Most young, single, healthy, and unskilled lower-to-middle income males living in emigration-prone regions of Europe in the early 1900s could legally and readily access relatively attractive employment opportunities in America, but did not do so, and because of the uncertain realization of the rewards, not because of the upfront costs of pursuing them. In general, the minority of Europeans willing and able to countenance the risks of migration, especially the risk of becoming jobless in an American economic slump, and to arrange, through kinship chains, for dependent family members to follow them, were the ones who emigrated. Strategies of passenger shipping firms were also dominated by risk management (not fare reductions, cost minimization, or short-term profit maximization). Government migration policies emphasized cautionary concerns as well, particularly the practical challenges of crowd management.

These various strategies for coping with the risks of mass migration overlapped more than they conflicted with each other. Interwoven strategies for managing the risks of early twentieth century transatlantic migration help account for the broad complexity of that human relocation, and to reveal the underlying motivations and processes of modern long-distance migration more generally.