By Donna R. Gabaccia, Director, Immigration History Research Center
In debates about immigration, Americans prefer watery metaphors--of waves or streams of migrants washing into the United States. Maybe that's why so many imagine that their government can simply "turn off the tap." World historians explain why such faucets don't always work.
This week my graduate students and I are reading world historians. The scale of their analyses is breathtaking. See one effort to re-tell the history of the earth and its peoples in a seven-minute video: http://worldhistoryforusall.sdsu.edu/movies/flash_large.htm. A focus on the long-term history of human movements is equally humbling.
Historian Patrick Manning for example tells the story of how, in 30,000 years ago or so, "homo sapiens" walked out of Africa, along rivers and coasts, through mountain valleys and across vast plains to populate every corner of Europe, Asia, and the Americas. Manning stops short of describing humans as a mobile species, although in his book Migration in World History, he distinguishes humans' cross-cultural movements to the migratory habits of birds and wildebeests. He also suggests that migration may be the most important source of innovation and change in human history.
Dirk Hoerder too portrays a world on the move in every era and indeed every decade. Hoerder demonstrates how normal migration has been and how many human beings have expected to move at some point in their lives. The Lucasssen brothers, Leo and Jan, put to rest a common assumption that it was modernization that transformed "naturally" sedentary people into restless migrants. And historian Adam McKeown dismisses the notion that Europeans have been uniquely mobile or innovative for he documents Asians as equally restless, whether in crossing the Pacific or expanding relentlessly into every corner of their own vast continent.
It's hard to read the world historians without forming a graphic image of the earth as a kind of teeming anthill, where people are constantly venturing off in one direction or another, for shorter or longer times, in search of food, of adventure, of opportunity, of material comfort or of a better meal, of education, of work or of safety. Historians like Hoerder do acknowledge the emotional stresses, the separations from loved ones, the cultural shocks and even the exploitation and oppression that can accompany migration. But almost no one can read these world histories of migration without questioning whether most humans would prefer a sedentary life or whether barriers to movement can easily be erected to "stem the tide." On the contrary, if humans are a mobile species, and if mobility is the engine of development, why have so many nations around the world sought to restrict it? That is the question world historians pose.