… He spoke very angrily, and was excited. Perhaps he was indirectly addressing me, as a northern man, on the general subject of fugitive slaves. I said that it was necessary to have special treaty stipulations about such matters. The Mexicans lost their peons — bounden servants; they ran away to our side but the United States government never took any measures to restore them, nor did the Mexicans ask it. “But,” he answered, in a tone of indignation, “those are not niggers, are they? They are white people, just as white as the Mexicans themselves, and just as much right to be free.”
Frederick Law Olmsted, A Journey in the Back Country. New York: Mason Brothers, 1860. 173.
[mid-1850s convo, 1860 publication, dialectical context: staying at a plantation in “The Interior Cotton Districts,” already speaking about fugitive black slaves across the U.S.-Mexico line and why slave-catchers cannot go there to capture them]