shelter afforded by the timber, the forests yield food more easily captured, as well as material for his habitation and for his implements of war and the household; while the annual devastation by fire rendered the prairie not only uninhabitable, but actually dangerous. It is certain, therefore, that the occupancy of the prairies has been, in general, the latest step in the establishment of the dominion of the aboriginal tribes. In other words, it is only a late migration which has brought the Siouan tribes into the plains of the Missouri and of the upper Mississippi, and with this fact agrees all the evidence that can be found that bears on it, whether from a study of the people themselves, of the mounds, or of their traditions.
It will be anticipated, from what has been said thus far, that the original mound-builder dynasty in the Ohio Valley was destroyed by an incursion of hostile people belonging to the Algonquian stock. It will be the burden of the rest of this paper to establish that great prehistoric event, and to show what effect it had on Minnesota.
Dr. Cyrus Thomas is to be accredited with the most thorough investigation of the aboriginal earthworks of the country. Under the direction of the Bureau of Ethnology he has established some important generalizations and has traced out some of the movements of the tribes that were concerned in the war which resulted in the expulsion of the original mound-builders from Ohio and the contiguous regions. Suffice it to say here that he considers that the evidence shows a movement, at least an extension, of the earliest mound-builders from the region of eastern Iowa, southeastern Minnesota, and southwestern Wisconsin, across Illinois and Indiana into Ohio. He shows that these people were driven out toward the east and southeast. He traces this retreat, which may have required several hundred years for its completion, with the most patient and convincing research, and arrives at the conclusion that when the whites came upon the scene the defeated and expelled people were known as Cherokee, living in western North Carolina and eastern Tennessee, and were still building mounds. The last statement is abundantly verified, even by historic documents. De Soto met them in his trip across the cis-Mississippi region, and his chroniclers describe the mounds which they saw. Some of the mounds built by the Cherokee in their new home contain articles of European manufacture.
But this line of persistent aggression from the northwest to the southeast, resulting in the expulsion of the Cherokee from the upper part of the Ohio Valley, was not the whole of the great war, though it is the only part that has been established by evidence like that adduced by Dr. Thomas. It can hardly be questioned that such an incursion would have had a disastrous effect on the mound-builders of the whole Ohio Valley, and that they were all driven out at the same time and by the same hostile force.