But most insidious of all in keeping the Indian inimical to his white neighbors was the influence of the fur traders--especially those of the American Fur Company. The admitted purpose of this organization was to keep the Indian a savage hunter and at the same time to frighten the white settlers away from the frontier in order that the annual crop of cheaply obtained but valuable furs might not suffer diminution. To keep the Indian in such a condition it was necessary to prevent him from assuming too friendly an attitude toward the whites--in order that he might the better beat back or discourage their westward advance. There were strong suspicions that more than one attack upon border settlers by Indians occurred because the presence of these settlers threatened the fur-gathering preserves of the American Fur Company. It would be wrong, however, to create the impression that the fur traders operated in secret. Practically everyone knew their purpose and methods: their purposes they openly admitted, and their methods consisted largely in dispensing “fire water” and in selling to the Indian on credit. The latter practice was useful, for it obligated the Indian to serve the Company in realizing its ends. Perhaps the most notable example of the Company’s interference with plans of Indian amelioration is to be found in the case of the Winnebagoes. Their agent, Joseph M. Street, one of the most enlightened Indian agents the Iowa country ever knew, had for some years been striving to improve the condition of the Winnebagoes, but without success. He had failed, not because his plan was impracticable, but because he came into direct conflict with the purposes and methods of the American Fur Company.[55] IV THE GRINDSTONE WAR AND THE DEATH OF SIDOMINADOTA The strained relations between the whites and the Indians resulted in unfortunate incidents which served to intensify the bad feeling already engendered. Of these, two may be noted as especially significant in the frontier history of northwestern Iowa. Thus, in 1854 and 1855, the so-called “Grindstone War” caused the whites to abandon the frontier for a time and spread alarm far and near. This incident might properly be said to have had its origin in intertribal hatred.