Historians have long tethered American overland migration to U.S. westward expansion, and they have presumed that Americans who left U.S. borders for Oregon and California in the early 1840s desired—and even assumed—that the United States would soon conquer the Far West. This article examines the words and actions of western migrants before U.S. expansion in 1846. It argues that, in fact, migrants left U.S. borders because their economic prospects were poor in the United States and thus that most migrants cared little whether the United States conquered the West in the near future. Indeed, some of the more ambitious migrants were even hostile to U.S. expansion, for they longed for a western republic of their own. Ultimately, Americans who traveled west did not ascribe to the idea of the United States’ Manifest Destiny but instead were seeking their own individual destinies.
The mid-nineteenth century territorial growth of the United States was complex and contradictory. Not only did Mexico, Britain, and Native Americans contest U.S. territorial objectives; so, too, did many within the United States and in some cases American western settlers themselves. The notion of manifest destiny reflects few of these complexities. The authors argue that manifest destiny was a partisan idea that emerged in a context of division and uncertainty intended to overawe opponents of expansion. Only in the early twentieth century, as the United States had consolidated its hold on the North American West and was extending its power into the Caribbean and Pacific, did historians begin to describe manifest destiny as something that it never was in the nineteenth century: a consensus. To a significant extent, historians continue to rely on the idea to explain U.S. expansion. The authors argue for returning a sense of context and contingency to the understanding of mid-nineteenth-century U.S. expansion.