“Almost from the very first, the perceptive plains Indians had recognized the threat the overland caravans represented to their way of life. Therefore, one of their first responses was to demand tribute of the passing trains. This tactic was employed at least as early as 1843. An 1845 overlander, speculating on the origins of this Indian tax, believed the practice to have begun with frightened emigrants willing to promise almost anything to travel safely. But it seems clear that tribute demands, which were most widely experienced by overlanders during the gold rush period, were grounded in more than simple repetition of a previous chance success. Emigrants continually reported that the Indians who came to demand tribute explained also why they were requesting the payments. The natives explicitly emphasized that the throngs of overlanders were killing and scaring away buffalo and other wild game, overgrazing prairie grasses, exhausting the small quantity of available timber, and depleting water resources. The tribute payments were demanded mainly by the Sac and Fox, Kickapoo, Pawnee, and Sioux Indians—the tribes closest to the Missouri River frontier and therefore those feeling most keenly the pressures of white men increasingly impinging upon their domains. . . .
[E]migrants differed in their responses to this form of native entrepreneurship. What [emigrants who threatened force] did not acknowledge was the cumulative impact of a series of such arrogant actions. . . .
The bridge tolls and tribute payments demanded by the Indians were insignificant when compared to the ferry and bridge charges asked by mountain men and traders farther west along the trails. Clearly, however, it was not the money as much as the idea that Indians had any ‘right’ to claim payments which infuriated many emigrants. Indignantly refusing compliance, these emigrants willingly instigated skirmished, which in turn elicited Indian retaliation on subsequent overlanders.”