I trace the origins of modern international arbitration to the late nineteenth-century Americas. I identify the appointment of Francis Lieber to the US–Mexican Commission of 1868 as the modern prototype of international arbitration. The US employed arbitration with Latin American countries differently than it did with Great Britain and other European states, mainly because of the US foreign policy known as the Monroe Doctrine. The US turn to international arbitration was a project that sought to protect US – not European or Latin American – interests. At the center of this practice was Secretary of State Hamilton Fish. Fish professionalized the State Department and, in the process, bolstered its resolution of diplomatic claims. From 1868 to 1898, US diplomats established international arbitration as the default tool of protecting its nationals who were injured within Latin America. The resulting international awards began to articulate rules regarding a state’s responsibility for injuries to aliens.

Humboldt also influenced a second generation of American linguists: Francis Lieber, who still had been a personal protégé of Humboldt’s and who studied Black English of South Carolina, English creoles of the Caribbean, and Chinook Jargon together with language acquisition; Albert S. Gatschet as a former student of the Humboldtian J. C. Eduard Buschmann in Berlin and as the only professional linguist at J. W. Powell’s Bureau of American Ethnology, studying diverse American languages; and Daniel G. Brinton, who examined Humboldt intensively, translated an essay of his on the verb in American languages into English, but misinterpreted Humboldt in social-evolutionist terms. Despite individual achievements, the second generation of American Humboldtians ultimately remained too disjointed to have much of a long-term impact, and Brinton appeared a renegade with his continued insistence on social Darwinism. When Brinton passed away, Humboldtian ideas evidently had little of a chance for survival in the United States.