[Sidenote: Origin of the Mound-Builders.]

But how remote the Mound-Builders were from the era of European
settlement, whence they came; how, whither, and when they
vanished,--these are questions before which science stands harassed,
impotent to answer positively. There are those who, marking certain
apparent resemblances between the implements, religious rites and
customs, and cranial formations, of the Mound-Builders, and those of
the Asiatic Mongols, conclude that the former were originally Asiatic
hordes, who, crossing Behring Straits, when, perhaps, the two continents
were united at that point, formed a new home and established a new
empire here. Others, with more proof, connect them with that great
Toltec race which occupied Central America and Mexico, before they were
driven out by the ruder and more warlike Aztecs.

[Sidenote: The Aztecs.]

The Toltecs have left ample records of their existence and gorgeous
civilization, in noble monuments and very numerous though till recently
undecipherable inscriptions; and many similarities lend weight to the
theory that the empire of the Mound-Builders, in the Ohio, Mississippi,
and Missouri valleys, was the result of a great Toltec migration from
Central America, which they left to Aztec dominion. Thus while we call
our continent the "New World," it is not improbable that we may be
living in a country which was alive with art, splendor, invention,
and power, when Europe was a dreary waste, over which the now extinct
monsters roamed unmolested by man.