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William O'Reilly - Faculty of History Small Grant Award July 2014

Defining migrants: cartography and the migration of peoples in the early modern world

William O'Reilly, Faculty of History, CAMMIGRES Small Grant Award, July 2014

Project summary

William O’Reilly’s work Selling Souls: the trafficking of German Immigrants: Europe and America 1648-1780 (Cambridge University Press, 2015, forthcoming) explores early modern German migration.  His in-depth exploration of the eighteenth century trafficking routes of German migrants brought to colonial America richly portrays the movement of ships of migrants smuggled from northern Switzerland by foot and barge to Rotterdam, before sailing across the Atlantic. Through the identification of every passenger on board one ship, O’Reilly traces the organisational work of a single trafficker, documenting the personal intricacies of people moving, including contacts, incomes, and the legality and illegality of departures (see Image 1: William O’Reilly’s Gephi schematic).  

Image 1: William O’Reilly’s Gephi Schematic - the ‘Facebook of the past’: This Gephi schematic results from a study of the transportation of poor emigrants, from northern Switzerland to Pennsylvania in 1749. The diagram is plotted on GPS locations, setting out the villages from which the emigrants came. The connective lines show how almost all of the 500 migrants who travelled on one ship, from Rotterdam to Philadelphia, were connected by trafficker, Johannes Tschudi. Over the course of his life, Tschudi was a prolific human trafficker, earning a substantial amount of money, escorting migrants from Switzerland and Germany to Rotterdam, where he sold them as ‘human freights’ to merchant shippers who transported the migrants in return for a contract of indenture. In this way, the emigrants became bonded labourers for periods of up to ten years. The resonances with contemporary migrations in the Mediterranean are obvious.

Contribution to the development of migration research

This work has led to the development of a range of UK and international collaborations, research proposals and publications which combine historical models and contemporary prospect theory to explore migrant decision-making processes, including the key questions of when, how and why migrants decide to embark on perilous journeys in the absence of reliable advance knowledge of their emigration destinations. These questions are salient in relation to contemporary migration flows, enabling an eighteenth century historian to begin to offer advisory contributions to EU policy-directives. In this vein O’Reilly is currently:

  • Undertaking research in the area of economic ‘prospect theory’ and migrant decision making: how, when and why do migrants decide to emigrate and how, potentially, could such decisions be influenced? This work combines research in behavioural economics, game theory and prospect theory with historical evidence gathered over the past years.
  • Contributing to an edited collection of essays (to be completed by 1 September 2015), with a chapter entitled “Choosing without knowing: How migrants choose a destination in the absence of real knowledge”. Versions of this research have been presented, on invitation, at Harvard and London.
  • Investigating the possibilities of, advising EU (and other) migration agencies on current migration flows, on migrant destination-choice and on strategies for addressing unpredictable migration flows.


Please note that the CAMMIGRES network has been superseded by the Centre for the Study of Global Human Movement.

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