Without taking up here the various theories respecting the origin, history, and disappearance of the Mound-builders, it may be well to express in a few brief conclusions what may be learned of this people by an examination of the monuments which they have left.
They were a numerous people, as is sufficiently proved by the magnitude and geographical extent of their works. They were probably one people, that is, composed of tribes living under similar laws, religion, and other institutions. Such variations as are observed in the monuments are only those that would naturally occur between central and frontier regions, although the animals-mounds of the north-west present some difficulties. The Mound-builders were an agricultural people. Tribes that live by hunting never build extensive public works, neither would the chase support a sufficiently large population for the erection of such works. Moreover, the location of the monuments in the most fertile sections goes far to confirm this conclusion. Some of the larger enclosures have been supposed,—only by reason of their size, however,—to have been cultivated fields; and evident traces of an ancient cultivation are found, although not clearly referable to the Mound-builders.
There is nothing to show an advanced civilization in the modern sense of the word, but they were civilized in comparison with the roving hunter-tribes of later times. They knew nothing of the use of metals beyond the mere hammering of native masses of copper and silver; they built no stone structures; they had seemingly made no approach to the higher grades of hieroglyphic writing. Their civilization as recorded by its material relics consisted of a knowledge of agriculture; considerable skill in the art of fortification; much greater skill than that of the Indians in the manufacture of pottery and the carving of stone pipes; the mathematical knowledge displayed in the laying-out of perfect circles and accurate angles, and in the correspondence in size between different works. Their earth-works show more perseverance than skill; no one of them necessarily implies the use of mechanical aids to labor; there is none that a large number of men might not construct by carrying earth in simple baskets.
All traces of their architecture have disappeared. It has been suggested that were the temples yet standing on their pyramidal foundations, they might compare favorably with those of Central America and Mexico. But the construction of wooden edifices with any pretensions to grandeur and symmetry, by means of stone and soft copper tools, seems absolutely impossible; at least such structures would require infinitely greater skill than that displayed by the Nahuas and Mayas, and it is more reasonable to suppose that the temples of the Mound-builders were rude wooden buildings.
The monuments imply a wide-spread religious system under a powerful priesthood; private devotion manifests itself on a scale less magnificent, and one involving less hard work. Of their rites we know nothing. The altar-mounds suggest sacrifice; burned human bones, human sacrifice. Gateways on the east, and the east and west direction of embankments and skeletons may connect worship with the sun; but all is conjecture. No idols, known to be such, have been found; the cemeteries, if any of them belong to the Mound-builders, show no uniform usage in burial. The ancient people lived under a system of government considerably advanced, more than likely in the hands of the priesthood, but of its details we know nothing. A social condition involving some form of slavery would be most favorable for the construction of such works.
The monuments described are not the work of the Indian tribes found in the country, nor of any tribes resembling them in institutions. Those tribes had no definite tradition even of past contact with a superior people, and it is only in the south among the little-known Natchez, that slight traces of a descent from, or imitation of, the Mound-builders appear. Most and the best authorities deem it impossible that the Mound-builders were even the remote ancestors of the Indian tribes; and while inclined to be less positive than most who have written on the subject respecting the possible changes that may have been effected by a long course of centuries, I think that the evidence of a race locally extinct is much stronger here than in any other part of the continent.
The monuments are not sufficient in themselves to absolutely prove or disprove the truth of any one of the following theories: 1st. An indigenous culture springing up among the Mississippi tribes, founded on agriculture, fostered by climate and other unknown circumstances, constantly growing through long ages, driving back the surrounding walls of savagism, but afterwards weakened by unknown causes, yielding gradually to savage hordes, and finally annihilated or driven in remnants from their homes southward. 2d. A colony from the southern peoples already started in the path of civilization, growing as before in power, but at last forced to yield their homes into the possession of savages. 3d. A migrating colony from the north, dwelling long in the land, gradually increasing in power and culture, constantly extending their dominion southward, and finally abandoning voluntarily or against their will, the north for the more favored south, where they modified or originated the southern civilization.
The last theory, long a very popular one, is in itself less consistent and receives less support from the relics than the others. The second, which has some points in common with the first, is most reasonable and best supported by monumental and traditional evidence. The temple-mounds strongly resemble in their principal features the southern pyramids; at least they imply a likeness of religious ideas in the builders. The use of obsidian implements shows a connection, either through origin, war, or commerce, with the Mexican nations, or at least with nations who came in contact with the Nahuas. There are, moreover, several Nahua traditions respecting the arrival on their coasts from the north-east, of civilized strangers. There is very little evidence that the Mound-builders introduced in the south the Nahua civilization, and none whatever that the Aztec migration started from the Mississippi Valley, but I am inclined to believe that there was actually a connection between the two peoples; that the Mound-builders, or those that introduced their culture, were originally a Nahua colony, and that these people may be referred to in some of the traditions mentioned. Without claiming to be able to determine exactly the relation between the Mound-builders and Nahuas, I shall have something further to say on this subject in another volume.
ANTIQUITY OF THE MONUMENTS.
The works were not built by a migrating people, but by a race that lived long in the land. It seems unlikely that the results attained could have been accomplished in less than four or five centuries. Nothing indicates that the time did not extend to thousands of years, but it is only respecting the minimum time that there can be any grounds for reasonable conjecture. If we suppose the civilization indigenous, of course a much longer period must be assigned to its development than if it was introduced by a migration—or rather a colonization, for civilized and semi-civilized peoples do not migrate en masse. Moreover a northern origin would imply a longer duration of time than one from the south, where a degree of civilization is known to have existed.