Essays consider both the nineteenth century, when the international border had limited power to restrict the movement of Native peoples, financial capital, or settlers’ racist attitudes, and the strengthened boundary of the twentieth century, with its disputes over salmon runs, free trade, and World War II defence. Essays also explore the ways in which Canada and the United States have defined and preserved wilderness, the 1840s dispute over the Oregon Country, and U.S. attitudes that have provoked anti-Americanism in Canada. The U.S.-Canadian border has meant different things to different people, and those meanings have changed over time. The situation today is the result of the evolution in cross-border integration that took place in the past; each side of this borderlands region remains, in part, the creation of the other. Contributors are Carl Abbott, Ken Coates, Michael Fellman, John Findlay, John Lutz, Daniel P. Marshall, Jeremy Mouat, Galen Roger Perras, Chad Reimer, Joseph E. Taylor III, Patricia K. Wood, and Donald Worster.