Spanish American Independence and the Discourse of U.S. Pacific Expansion, 1815–1830

Historians have long understood the collapse of the Spanish Empire as a pivotal event that contributed to the United States’ territorial expansion to the Pacific coast. But before the era of aggressive antebellum expansion, U.S. expansionists had begun to increasingly contemplate a future on the Pacific coast amid an era of pan-American unity. In the 1810s and 1820s, U.S. policymakers and citizens embraced the aspirations of Spanish American revolutionaries, who argued that their independence would transform the Pacific world. At a moment when U.S. expansion to the Pacific coast proved tenuous, U.S. expansionists drew upon Spanish Americans’ vision of commercial liberation, inter-American cooperation, and transoceanic canals to imagine sustaining a distant settler colony in the Columbian River basin. When independent Spanish America did not live up to these lofty expectations by the mid-1820s, however, U.S. policymakers and expansionists corrupted Spanish Americans’ vision to justify annexing California and Mexico’s Far North. What had been a pan-American fantasy of Pacific expansion had become the highly aggressive, imperialistic language associated with antebellum aggrandizement. Before antebellum expansionists clamored for war with Mexico, Americans imagined spreading their nation from sea to shining sea with the help of their southern sister republics.