Ruins and other vestiges revealing an ancient civilization are found
throughout the whole southern section of North America, extending as far
north as New Mexico and Arizona. But here the antiquities do not all
belong to the same period in the past, nor exhibit unvarying likeness
and unity of civilized life. They are somewhat less homogeneous, and do
not constantly represent the same degree of civilization. In this
region, the monuments suggest successive and varying periods in the
civilized condition of the old inhabitants, some of the oldest and most
mysterious monuments seeming to indicate the highest development.
In the northern part of this region we find ruins of great buildings
similar in plan and arrangement to those still used by the Pueblos, but
far superior as monuments of architecture, science, and skill, and much
more unlike those farther south than is apparent in the principal
structures of the Mound-Builders. They show that the old settlers in the
Mississippi Valley did not belong to the Pueblo branch of the Mexican
race. Farther south, in the central part of the region specified,
development was more advanced. Here, in the last ages of American
ancient history, was the seat of the Mexican or Aztec civilization,
but the monuments in this part of the country are mostly older than the
Aztec period. The most astonishing remains are found still farther
south, in Chiapa, Tabasco, Oxaca, Yucatan, Honduras, Tehuantepec,
Guatemala, and other parts of Central America. In this southern region,
mostly buried in heavy forests, are wonderful ruins of great cities and
temples. Only a small part of modern Mexico is included in the region
where these ruins are situated, and most of them, probably, were not
much better understood by the ancient Mexicans than they are by us. Many
of those explored in later times were unknown to that people, just as
others, more in number, doubtless, than those already described, still
remain unvisited and unknown in the great and almost impenetrable
forests of the country.