Like all the neighboring states, Illinois has long been noted for the various mounds and earthworks within her borders, and the nature of these aroused the curiosity of even the first settlers in the territory. For many years theories of all sorts were current, attributing the mounds to a race of "mound-builders" who, according to the predilections of the different writers, were supposed to have come direct from Asia, Mexico, or even more remote places. In the latter part of the last century the Bureau of American Ethnology undertook a survey of the mounds in the eastern United States.  The reports which resulted from this work did much to foster a saner view of the problem and to bring it from the realms of wild speculation to those of science. Much intensive work remains to be done in Illinois before we may hope to trace accurately the cultural development of the region, but from the work so far completed the following general facts stand out.

While many of the mounds are doubtless prehistoric, some of them, representing practically every type in the state, have been proved by their contents to be post-Columbian. A great amount of historical evidence, moreover, clearly shows that the Indians occupying the mound region at the time they were visited by the first explorers, were actually "mound builders," and raised both towns and places of worship on these artificial eminences. The human remains found in the mounds that have been excavated to date, are all of the American Indian type, and represent only the recent period of geologic time.

In northern Illinois none of the mounds appears to have been used for temple or village foundations. Several types occur, the most striking being the effigy mounds which seem to represent reptiles, birds, or mammals in shape. In Wisconsin where the type is most numerous, they appear to have been the work of the ancestors of the Winnebago, and nearby peoples of Siouan stock. The accounts of these peoples speak of the mounds as representing the totem animals of their clans. The Illinois effigy mounds may have the same origin. A few large oval mounds occur, and there are large numbers of small round burial mounds as well. Along some of the low hills are found walls two or three feet high and sometimes four hundred yards long. Like the effigy mounds these earthworks rarely contain burials. Their use is problematical, and while they are spoken of as "fortifications," their strategic value is not clear. Stone-lined graves, or cists, are found containing rather primitive grave gifts. Loskiel described actual burials among the Delaware Indians made in this manner, and similar graves known to be Shawnee occur in the south.

In southern Illinois many of the mounds, such as the Cahokia group, appear to have been eminences for temples or habitations. The tribes who built this type of artificial eminence are not known, though the. Cherokee of northern Georgia and North Carolina made use of similar mounds for village and temple sites in early historic times. It is possible that peoples allied to the Cherokee, at one time occupied the river valleys to the north, and were driven out prior to the advent of the white man. In this connection it is interesting to note that recently a type of prehistoric culture similar to that of the Iroquois has been distinguished in southern Illinois. It is possible that the latter people may have been partly responsible for the disappearance of the older "mound builders" in southern Illinois, as well as in Ohio. Such in general is the character of the archaeological evidence in the region under consideration, although it is certain that more intensive archaeological work will establish a clearer time sequence and settle many of the problems which exist.