Alongside individual murders and crimes, the federal government also confronted in the territories a long-standing borderlands law governing organized violence. Both Natives and whites there conducted larger-scale, often brutal expeditions against each other, often with little or no formal authorization from their ostensible governments. The federal government sought to replace this seemingly pathological culture of violence by imposing a definition of war drawn from the newly adopted U.S. Constitution that made the federal government, and particularly Congress, the sole arbiter and source of legitimate violence against Native nations. The effects of this federal assertion of supremacy differed in the two territories. In the Northwest Territory, the conflict known as the Northwest Indian War expanded earlier practices of borderlands violence under federal auspices. Citizens of the Southwest Territory demanded the same, and nearly got it, in what this chapter terms the war-that-nearly-was. What actually followed in the Southwest Territory instead was an intense, polyvocal legal contest between territorial citizens and officials, Congress, the Washington administration, and the Creek, Cherokee, and Chickasaw Nations over the meaning of the categories of war and peace. Yet again, federal officials failed to establish federal supremacy, but they did succeed in insinuating federal law into territorial life and Indian country, including disputes between Native nations.