III. Minor relics of aboriginal art, for the most part taken from the mounds, including implements and ornaments of metal, stone, shell, and bone.
IV. Ancient mines, and perhaps a few salt-wells which bear marks of having been worked by the aborigines.
V. Rock-inscriptions.
These different classes of remains, although sufficiently uniform in their general character to indicate that the Mound-builders were of one race, living under one grand system of institutions, still show certain variations in the relative predominance of each class in different sections of the territory. The Ohio River and its tributaries would seem to have been in a certain sense the centre of the Mound-builders' power, for here the various forms of enclosures and mounds are most abundant and extensive, and their contents show the highest advancement of aboriginal art. This section, including chiefly the state of Ohio, but also parts of Kentucky, Indiana, Tennessee, Illinois, and Missouri, was the ground embraced in the explorations of Squier and Davis, by far the best authorities on eastern antiquities. In the northern region, on the great lakes, on which Lapham and Pidgeon are the prominent authorities, chiefly in Wisconsin, but also in Michigan, Illinois, Missouri, Iowa, and Minnesota, animal-mounds are the prominent feature, the other classes of mounds, and the enclosures, being of comparatively rare occurrence. The animal-mounds occur in the central Ohio region only in a very few instances, and never, so far as is known, in the south. In the southern or gulf states the temple-mounds are more numerous in proportion to other classes than in the north, and enclosures disappear almost altogether. The southern antiquities have, however, been comparatively little explored, Mr Jones' late work referring for the most part only to the state of Georgia.
Throughout the whole region traces of the tribes found by Europeans in possession of the country are found; and besides the three territorial divisions already indicated, it is noted that in the north-east, in western New York and Pennsylvania, the works of the Mound-builders merge so gradually into those of the later tribes, the only relics farther east, that it becomes well-nigh impossible to fix accurately the dividing line.
REMAINS IN NEW YORK.
In many parts of western New York traces are found of Indian fortified camps, surrounded by rows of holes in the ground, which once supported palisades, and in all respects similar to those in use among the Indians of the state in their wars against the whites. There are also found low embankments of earth, or very rarely of small stones, which form enclosures or cut off the approach to the weaker side of some naturally strong position. Such embankments are always on hills, lake or river terraces, or other high places, and are often protected on one or more sides by morasses or by streams with steep banks. Their strong natural position, with due regard to the water supply, carefully planned means of exit, and in many instances graded roads to the water, leaves no doubt of their original design as fortifications, places of refuge and of protection against enemies. The slight height of the embankments would suggest that they were thrown up to support palisades; indeed, traces of these palisades have been found in some cases. The practice of throwing up an embankment at the foot of palisades, although seemingly a very natural one, does not, however, seem to have been noticed among the Indian tribes of New York. In nearly all the enclosures remains of the typical Indian caches are found, with carbonized maize, and traces of wood and bark; and in and around them the sites of Indian lodges or towns are seen, indicated by the presence of decomposed and carbonaceous matter, together with burned stones, charcoal, ashes, bones, pottery, and Indian implements. These circumstances go far to prove that all the New York works, if not built by the Indians, were at least occupied by them after their abandonment by the Mound-builders, from some of whose works they do not differ much except in dimensions and regularity of form.
The enclosures vary in extent from three to four acres, the largest being sixteen acres. The embankments are from one to four feet high, generally accompanied by an exterior ditch;—the highest is seven or eight feet from bottom of ditch to top of embankment. Many such works in a country so long under cultivation have of course disappeared. Mr Squier ascertained the locality of one hundred of them in New York, and estimates the original number at not less than two hundred and fifty.
The works of the Mound-builders are almost exclusively confined to the fertile valleys still best fitted to support a dense population. The Mississippi and its tributaries have during the progress of the centuries worn down their valleys in three or four successive terraces, which, except the lowest, or latest formed, the ancient peoples chose as the site of their structures, giving the preference in rearing their grandest cities—for cities there must have been—to the terrace plains near the junction of the larger streams. On these plains and their surrounding heights, are found the ancient monuments, generally in groups which include all or many of the classes named above; for it is only for convenience in description that the classification is made; that is, the classification is by no means to any great extent a geographical one. I have already said that Ohio was the centre, apparently, of the Mound-builders' power. Northward, eastward, and perhaps westward from this centre, the works diminish in extent, fortifications become a more prominent feature, and the remaining monuments approximate perceptibly to those of the more barbarous and later peoples. In fact, we find the modifications that might naturally be expected in a frontier country. Southward from the Ohio region down the Mississippi Valley, it is a common remark in the various writings on the subject, that the monuments increase gradually in magnitude and numbers. This statement seems to have originated, partially at least, in the old attempt to trace the path of Aztec migration southward. The only foundation for it is the fact that the class of mounds called temple-mounds are in the south more numerous in proportion to those of the other classes. The largest mound and the most extensive groups are in the north; while the complicated arrangement of sacred enclosures appears but rarely if at all towards the gulf. It is not impossible that more extensive explorations may show that the comparative numbers and size of the large temple-mounds have been somewhat exaggerated. Yet the claims in behalf of Nahua traces in the Mississippi region are much better founded than those that have been urged in other parts of the country; although we have seen that the chain is interrupted in the New Mexican country, and I can find no definite record of temple-mounds in Texas. The total number of mounds in the state of Ohio is estimated by the best authority at ten thousand, while the enclosures were at least fifteen hundred.
FORTIFICATIONS.