Abstract: By 1900, and continuing until the outbreak of World War I in 1914, most Europeans could legally and readily access well-developed transport and support network linkages to relatively attractive employment opportunities in the United States of America. Despite the clear advantages of doing so, however, most Europeans did not move to the United States during these years. Prior historical analyses generally assume that migration volumes were constrained by cost barriers, that oceanic travel expense made up the bulk of such costs, and that transport companies' strategies were based on a trade-off between competing for migrants on price and exploiting migrants by overcharging them. This dissertation presents evidence refuting all these assumptions and reveals instead a set of overlapping and interrelated risk management strategies. Although it was economically advantageous for migrants, the steamship lines transporting them, and the economies of sending and receiving countries, early twentieth century transatlantic migration was inherently risky for all these parties. Coping with risk was a central component of their policies towards and involvement with migration. The most important forms of such risk amelioration were congruent and cooperative measures amongst and between migrants, shipping companies and government regulatory agencies.