The story of the Sioux who moved into the Canadian-American borderlands in the later years of the nineteenth century is told in its entirety for the first time here. Previous histories have been divided by national boundaries and have focused on the famous personages involved, paying scant attention to how Native peoples on both sides of the border reacted to the arrival of the Sioux. Using material from archives across North America, Canadian and American government documents, Lakota winter counts, and oral history, Living with Strangers reveals how the nineteenth-century Sioux were a people of the borderlands. The Sioux made great tactical use of the Canada–United States boundary. They traded with the Métis of Canada—often in contraband goods such as arms and ammunition—and tried to get better prices from European traders by drawing the Hudson’s Bay Company into competition with American traders. They opened negotiations with both Canadian and American officials to determine which government would accord them better treatment, and they used the boundary as a shield in times of warfare with the United States. Until now, the Canadian-American borderlands and the people who live there have remained a blind spot in Canadian and American nationalist historiographies. Living with Strangers takes readers beyond the traditional dichotomy of the Canadian and the American West and reveals significant and previously unknown strands in Sioux history.