From what is seen in the Southern and Western States antiquarians have reached the following conclusions: 1. The so-called Mound Builders were no wandering and feeble tribes, but constituted a large population under one central government; this is shown by the extent of the works, as well as their completeness and scientific exactness. 2. A large area around their settlements was cleared of timber and cultivated, showing that they were an agricultural people. 3. As nature does not give a forest growth to abandoned fields, without a preparatory growth of shrubs and softer timber, and as forest trees have been found on their mounds showing at least six hundred years of growth, it follows that they left our country nearly a thousand years ago. 4. From the increase of fortifications north-ward, and the broad flat mounds, suitable only for buildings southward, it is proven that at the South they were at peace; but as they advanced northward they came more and more into contact with the wild tribes, before whom they finally retired toward the south.

The excavations of the mounds show clearly that their builders had commercial intercourse with Mexico and Central America, and it seems probable that they had otherwise a very close relation to the people of those countries.

Antiquarians have therefore searched diligently in the few remaining books and traditions of the Mexicans, and Central Americans, for mention of the origin and history of the Mound Builders. Nor have they searched in vain. "It is believed," says Baldwin, "that distinct reference to their country has been found in the books still in existence, and there appears to be reason for this belief."

Brasseur de Bourbourg, one of the few investigators who have explored them, says: "Previous to the history of the Toltec domination in Mexico, we notice in the annals of the country two facts of great importance, but equally obscure in their details: First, the tradition concerning the landing of a foreign race, conducted by an illustrious personage, who came from an Eastern country; and, second, the existence of an ancient empire known as Huehue-Tlapalan, from which the Toltecs or Nahuas came to Mexico, in consequence of a Revolution or Invasion, and from which they had a long and toilsome migration to the Aztec plateau."

He believes that Huehue-Tlapalan was the country of the Mound Builders in the Mississippi and Ohio valleys. According to the native books he has examined, it was somewhere at a distance in the northeast; and it is constantly said that some of the Toltecs came by land and some by sea. Sahagun learned from the old books and traditions that the Toltecs came from that distant northeastern country; and he mentions a company that came by sea, settled near the Tampico River, and built a town called Panuco. Brasseur de Bourbourg finds that an account of this or another company was preserved at Xilanco, an ancient city situated on the point of an island between Lake Terminos and the sea, and famous for its commerce, wealth and intelligence. The company described in this account came from the northeast in the same way, it is said, to Tampico River, and landed at Panuco. It consisted of twenty chiefs and a numerous company of people. Torquemada found a record which describes them as people of fine appearance. They went forward into the country and were well received. He says they were industrious, orderly and intelligent, and that they worked metals and were skilful artists and lapidaries. All the accounts say the Toltecs came at different times, by land and sea, mostly in small companies, and always from the northeast. This can be explained only by supposing they came by sea from the mouth of the Mississippi River, and by land through Texas. But the country from which they came was invariably Huehue-Tlapalan.

Cabrera says Huehue-Tlapalan was the ancient country of the Toltecs. Its simple name was Tlapalan, but they called it Huehue, old, to distinguish it from three other Tlapalans which they founded in the districts of their new kingdom. Torquemada says the same. We are compelled to accept a fact so distinctly stated and so constantly reported in the old books, especially as the following statement is also made in connection with it, to account for the Toltec migration, that Huehue-Tlapalan was successfully invaded by Chichinecs, meaning Barbarous Aboriginal Tribes, who were united under one great leader. Here is the statement (a little condensed) touching this point:

"There was a terrible struggle, but, after about thirteen years, the Toltecs, no longer able to resist successfully, were obliged to abandon their country to escape complete subjugation. Two chiefs guided the march of the emigrating nation. At length they reached a region near the sea named 'Tlapalan-Conco,' where they remained several years. But they finally undertook another migration, and reached Mexico, where they built a town called 'Tollanzinco,' and later the city of Tullan, which became the seat of their government."

Brasseur de Bourbourg says: "In the histories written in the Nahuatl language, the oldest certain date is nine hundred and fifty-five years before Christ." If this date is authentic it would follow that the Nahuas, or Toltecs, left Huehue-Tlapalan more than a thousand years previous to the Christian era, for they dwelt a long time in the country of Xibalba as peaceable settlers before they organized the civil war which raised them to power. The Toltecs were in turn overthrown by the Aztecs, who held sway at the time of the Spanish conquest.

The Toltecs came originally from Mexico or Central America, and when they were expelled from the Ohio and Mississippi valleys by hordes of wild Indians from the north, they simply returned to their "Father Land"; but they had been absent so long they appeared as a different people. Baldwin well says "The fact that the settlements and works of the Mound Builders extended through Texas and across the Rio Grande indicates very plainly their connection with the people of Mexico, and goes far toward explaining their origin. In fact, the connection of settlements by way of Texas appears to have been unbroken from Ohio to Mexico. These people could not have come from any other part of North America, for nowhere else north of the isthmus was there any other people capable of producing such works as they left in the places where they dwelt. We have other evidence of intercourse between the two peoples; for the obsidian dug from the mounds, and perhaps the porphyry also, can be explained only by supposing commercial relations between them."

The Aztecs, whom the Spaniards found, were the last of at least three civilized races, and much inferior to the Toltecs immediately preceding them. Their history indicates that they were merely one of the original races, who overthrew and mingled with the Toltecs, adopting part of their religion and civilization. The Peruvian Incas, found by Pizarro, seem to have been the second of the series of races or dynasties. But civilization is of slow growth; it must have required at least a thousand years for the first of the three dynasties to have developed art and learning enough to erect the buildings we find. De Bourbourg and other antiquarians have given to that race before the Incas, the authors of the original civilization, the name of Colhuas.