Manifest Destiny Ideology Provides Racist Justification for Territorial Conquest and Indigenous Genocide

John L. O’Sullivan coins the term “Manifest Destiny” in 1845 to describe the expansionist belief that American settlers are destined to expand westward across North America, and that this expansion is both obvious (manifest) and certain (destiny). The ideology is rooted in American exceptionalism, romantic nationalism, and white nationalism, implying the inevitable spread of republicanism and the American way of life. However, critics recognize manifest destiny as an ideology used to justify dispossession and genocide against Indigenous peoples. The belief results in the forceful settler-colonial displacement of Indigenous Americans to carry out colonial expansion, ultimately leading to confrontations and wars with several groups of Native peoples through Indian removal policies. Manifest destiny becomes the ideological cover for territorial conquest that serves elite economic interests—land speculators, slaveholders, railroad interests, and mining companies—by providing a veneer of moral and historical inevitability to what is fundamentally theft, violence, and genocide.

The concept becomes particularly powerful during the 1840s as thousands of Americans migrate to the Oregon Country over the Oregon Trail (following the Anglo-American Convention of 1818 that provided for joint occupation). President James K. Polk employs manifest destiny rhetoric to justify the annexation of Texas (1845), war with Mexico (1846-1848), and claims to Oregon Territory. Continental expansion implicitly means the occupation and annexation of Native American land, sometimes to expand slavery. The Indian Removal Act of 1830, signed by President Andrew Jackson, authorized the forced displacement of self-governing tribes of American Indians from their ancestral homelands in the eastern United States to lands west of the Mississippi River—specifically to a designated Indian Territory (present-day Oklahoma)—which many scholars label genocide.

After enactment of the Indian Removal Act, approximately 60,000 members of the Cherokee, Muscogee (Creek), Seminole, Chickasaw, and Choctaw nations (including thousands of their Black slaves) are forcibly removed from their ancestral homelands, with thousands dying during the Trail of Tears. Raphael Lemkin, who coined the term “genocide,” considered the displacement of Native Americans by European settlers as a historical example of genocide. While description as genocide has found increasing acceptance within Indigenous and genocide studies, mainstream scholarship on U.S. and Native American history has largely rejected it, preferring to describe it as ethnic cleansing or certain events as genocidal—a semantic debate that obscures the systematic nature of Indigenous displacement and death.

The California example demonstrates the genocidal results of manifest destiny ideology: the pre-Columbian population of California was around 300,000. By 1849, due to epidemics, the number had decreased to 100,000. But from 1849 to 1870, the indigenous population of California falls to 35,000 because of killings and displacement—a 65 percent reduction in two decades. At least 4,500 California Indians are killed between 1849 and 1870, while many more perish from disease and starvation. In June 2019, California Governor Gavin Newsom apologizes for the genocide, saying: “That’s what it was, a genocide. No other way to describe it. And that’s the way it needs to be described in the history books.” Manifest destiny demonstrates how ideological justifications for institutional corruption function: by cloaking elite economic interests (land acquisition) in the language of historical inevitability, moral superiority, and civilizational progress, the ideology enables systematic violence and dispossession while obscuring the kakistocracy—rule by the worst, most unscrupulous elements of society—that drives territorial expansion for private profit.