ANCIENT HISTORY OF NORTH AMERICA. 429 



iuteiTuptcd by smaller monnds. Their dimensions are enormous. Some 

 are as high as 00 feet, and have a length of from 500 to 700 feet at the base. 

 The upper surface of the great pyramid in Washington County, Missouri, 

 contains 12,000 square feet. It is the largest of a group of eleven of 

 such mounds. These mounds are either found alone or in groups ; some 

 are surrounded by earth-walls and others are not. Besides those of the 

 Mississippi Yalle}', similar large earth-pyramids are found in the Colorado 

 Valley, where they are considered as Aztec structures. They have un- 

 mistakable signs of former buildings upon them. Probably these earth- 

 works had no other object than to serve as elevated bases for temples 

 and the houses of chiefs and priests. These buildings must have been 

 formed of lighter material, for they have entirely disappeared. Kever- 

 theless they remind us of similar but more perfectly executed buildings 

 of a later time in Mexico and Central America. All investigators agree 

 that their builders belonged to a much higher civilization than those of 

 the smaller grave-mounds in the east, or the Indians of the present day. 

 It is said that the utensils from these mounds are worked with much 

 more skill, and that some among them justified the conclusion that the 

 builders followed agricultural pursuits. Another remarkable circum- 

 stance is, that now and then copper utensils were found in the posses- 

 sion of the Indians on the Atlantic coast. These, however, can only 

 have been such as they found among the remains of the more ancient 

 race ; since investigations of the Lake Superior copper region prove 

 that the knowledge of making use of these copper-ore deposits had 

 already been lost at the time when the Europeans took possession of 

 America. Indeed, copper utensils are found only in the earth-works of 

 the older, but not in the mounds of the more recent period. 



The mere presence of these large earth-works, however, with their 

 incl»sures or bulwarks, is sufficient proof of a more highly developed 

 people, who were no longer nomadic. I cannot help tliiidving that the 

 Mississippi Valley may have been at one time the home of the Aztecs 

 and Toltecs, who there erected, so to speak, the first crude models of 

 their later wonderful structures, and then moved southward from un- 

 known causes, carrying with them their higher civilization, and develop- 

 ing it still further in their new homes; while the inferior race, which 

 took possession of their abandoned dwellings, remained without knowl- 

 edge of the rich ore dej^osits. 



There are also earth-works of another kind, similar to those in the 

 Atlantic States, which doubtless served as fortifications. Some probably 

 were inclosures of small villages ; for they are usually found near sin- 

 gle or around whole groups of mounds, and have the ditch on the inner 

 side. They frequently inclose large areas, but not a trace is left of the 

 dwellings, which may have been within. 



A very peculiar species of earth-works are in the shape of men or 

 various animals, the outlines of which they represent. Perhaps these 

 partook of a religious or national character, some of the tribes being- 

 named after certain animals. 



