Between 1860 and 1930, the Canada-United States border emerged as a crucial economic boundary. In creating the border, however, Canada and the United States prioritized revenue generation over coherence or uniformity. This priority created an unpredictable barrier for both businesses and individuals. Consuls often focused their attention on understanding the impacts of tariffs, trade volume, and smuggling on transnational commerce. The border’s practical impacts, however, went far deeper. For individuals, the border’s unpredictability shaped everything from how they gave gifts to the ways they supported their families. For businesses, the border impacted profit margins and intellectual property. But it also changed how businesses approached administrative tasks—everything from staff training to who they delegated to fill out paperwork. Although imagined as a federal project, the border’s tolerances for variation ensured that regional and local solutions proliferated. Federal mandates merged with local interests to create an inconsistent barrier of ever-changing heights.

Both historians of science and Americanists have depicted famed nineteenth-century astronomer and political economist Simon Newcomb as a relatively stern “mugwump,” impressive in his scientific achievement, yet at times stunted by a parochial arrogance. In histories of nineteenth-century liberalism, in particular, Newcomb makes cameos as a stand-in for an economically conservative wing. This article analyzes two facets of Newcomb’s postwar thinking that have been consistently left out: race and nationalism. After the Civil War, Newcomb pushed a nationalist discourse of American scientific progress in The North American Review that at times wavered between cultural and biological determinism. He spoke in terms of national styles and believed that American science, opposed to French, German, or English science, languished. His advocacy for an American science rested upon implicit “ethnoracial” nationalist assumptions. Contrary to his laissez-faire liberalism, it called for a more activist scientific state, and feared a nationalism of apathy that he believed pervaded both American science and politics. This article, moreover, argues that Newcomb’s thought was intimately tied to his experiences in postbellum Washington, suggesting the need for more localist and urban studies of the rise of state science after the Civil War.