On the eve of the American Revolution, Anglo-Americans had developed a conception of themselves as a continental society. This self-conception seems illogical by modern standards. After all, these colonists occupied only a narrow strip of land along the coast, a much smaller portion of America than New Spain. Nevertheless, the assumption of continental status helped unite Anglo-Americans in their struggle with Britain. They dealt with British tyranny by developing Continental Associations, a Continental Congress, and a Continental Army. This essay argues that the continental metaphor had its roots in an array of scientific theories and trends with origins on both sides of the Atlantic. It also argues that Anglo-Americans engaged these theories and trends as they did because of their unique social context and historical development. In a final section comparing the science of Thomas Jefferson with that of the protonationalist Mexican Francisco Clavigero, this essay shows how the historical memory of the two affected both scientific and political discourse. The result was that continents took on much greater importance in mainland British North America than in Mexico. In Anglo-America, scientific beliefs drew sustenance from history and fueled a sense of destiny.