They were unquestionably American aborigines, and not immigrants from
another continent. That appears to me the most reasonable suggestion
which assumes that the Mound-Builders came originally from Mexico and
Central America. It explains many facts connected with their remains. In
the Great Valley their most populous settlements were at the south.
Coming from Mexico and Central America, they would begin their
settlements on the Gulf coast, and afterward advance gradually up the
river to the Ohio Valley. It seems evident that they came by this route;
and their remains show that their only connection with the coast was at
the south. Their settlements did not reach the coast at any other point.
Their constructions were similar in design and arrangement to those
found in Mexico and Central America. Like the Mexicans and Central
Americans, they had many of the smaller structures known as _teocallis_,
and also large high mounds, with level summits, reached by great flights
of steps. Pyramidal platforms or foundations for important edifices
appear in both regions, and are very much alike. In Central America
important edifices were built of hewn stone, and can still be examined
in their ruins. The Mound-Builders, like some of the ancient people of
Mexico and Yucatan, used wood, sun-dried brick, or some other material
that could not resist decay. There is evidence that they used timber for
building purposes. In one of the mounds opened in the Ohio Valley two
chambers were found with remains of the timber of which the walls were
made, and with arched ceilings precisely like those in Central America,
even to the overlapping stones. Chambers have been found in some of the
Central American and Mexican mounds, but there hewn stones were used for
the walls. In both regions the elevated and terraced foundations remain,
and can be compared. I have already called attention to the close
resemblance between them, but the fact is so important in any endeavor
to explain the Mound-Builders that I must bring it to view here.
Consider, then, that elevated and terraced foundations for important
buildings are peculiar to the ancient Mexicans and Central Americans;
that this method of construction, which, with them, was the rule, is
found nowhere else, save that terraced elevations, carefully
constructed, and precisely like theirs in form and appearance, occupy a
chief place among the remaining works of the Mound-Builders. The use
made of these foundations at Palenque, Uxmal, and Chichen-Itza, shows
the purpose for which they were constructed in the Mississippi Valley.
The resemblance is not due to chance. The explanation appears to me very
manifest. This method of construction was brought to the Mississippi
Valley from Mexico and Central America, the ancient inhabitants of that
region and the Mound-Builders being the same people in race, and also in
civilization, when it was brought here.
A very large proportion of the old structures in Ohio and farther south
called "mounds," namely, those which are low in proportion to their
horizontal extent, are terraced foundations for buildings, and if they
were situated in Yucatan, Guatemala, and Southern Mexico, they would
never be mistaken for any thing else. The high mounds also in the two
regions are remarkably alike. In both cases they are pyramidal in shape,
and have level summits of considerable extent, which were reached by
means of stairways on the outside. The great mound at Chichen-Itza is 75
feet high, and has on its summit a ruined stone edifice; that at Uxmal
is 60 feet high, and has a similar ruin on its summit; that at Mayapan
is 60 feet high; the edifice placed on its summit has disappeared. The
great mound at Miamisburg, Ohio, is 68 feet high; and that at Grave
Creek, West Virginia, is 75 feet high. Both had level summits, and
stairways on the outside, but no trace of any structure remains on them.
All these mounds were constructed for religious uses, and they are, in
their way, as much alike as any five Gothic churches.
Could these works of the Mound-Builders be restored to the condition in
which they were when the country was filled with their busy communities,
we should doubtless see great edifices, similar in style to those in
Yucatan, standing on the upper terraces of all the low and extended
"mounds," and smaller structures on the high mounds, such as those above
named. There would seem to be an extension of ancient Mexico and Central
America through Texas into the Mississippi and Ohio valleys; and so, if
there were no massive stone-work in the old ruins of those countries, it
might seem that the Mound-Builders' works were anciently extended into
them by way of Texas.
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 to explain their
origin. 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.
We can not suppose the Mound-Builders to 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. Beyond the relics of the Mound-Builders themselves, no
traces of the former existence of such a people have been discovered in
any part of North America save Mexico, and Central America, and
districts immediately connected with them. At the same time, it is not
unreasonable to suppose the civilized people of these regions extended
their settlements through Texas, and also migrated across the Gulf into
the Mississippi Valley. In fact, the connection of settlements by way of
Texas appears to have been unbroken from Ohio to Mexico.
This colonizing extension of the old Mexican race must have taken place
at a remote period in the past; for what has been said of the antiquity
of the Mound-Builders shows that a very long period, far more than two
thousand years, it may be, must have elapsed since they left the Valley
of the Ohio. Perhaps they found the country mostly unoccupied, and saw
there but little of any other people until an irruption of warlike
barbarians came upon them from the Northwest.
In speculating on the causes of their withdrawal after centuries of
occupation, absolute certainty is impossible, and we have no means of
going much beyond mere conjecture. We may suppose as most probable that
an influx of barbarians destroyed their border settlements, interrupted
their mining operations, and caused them to retire gradually toward the
Gulf. Fragments of their communities may have become incorporated with
the barbarous tribes. This conjecture has been used to explain certain
exceptional peculiarities noticed in some of the wild Indian tribes. For
instance, it has been suggested that the Mandan Indians were a separated
and lost fragment of the mound-building people, they being noticeably
unlike other Indians in many respects, lighter in color, and peculiar in
manners and customs. What is conjectured may be true, but we have no
means of proving its truth. That the Mandans were like what a lost
community of Mound-Builders might have become by degeneration through
mixture and association with barbarians may be supposed, but the actual
history of that remarkable tribe might give its peculiarities a very
different explanation. The Mandans were supposed to be a branch of the
Dacotahs. They may have been, like the Navajos, a changed community of
Pueblos, but any attempt to explain them by means of conjecture is
useless.
The supposition that the Toltecs and the Mound-Builders were the same
people seems to me not improbable. The reasons for it will be stated
when we come to a discussion of the antiquities, books, and traditions
of Central America. I will only say here that, according to dates given
in the Central American books, the Toltecs came from "Huehue-Tlapalan,"
a distant country in the northeast, long previous to the Christian era.
They played a great part and had a long career in Mexico previous to the
rise of their successors in power, the Aztecs, who were overthrown by
the Spaniards.