d Marietta was, undoubtedly, in
the days of the Mound-builders moving with a greater mass of human
beings than it can boast of to-day.

And if those peaceable and industrious inhabitants were as numerous as
their remains indicate, what must have been the strength of those
invading hordes who caused their downfall and perhaps wiped out
forever every living representative of that ancient race, who could
leave no more lasting memorial of their existence and struggles than
those mysterious mounds which have given them their name.

ANTIQUITY OF THE MOUND-BUILDERS.--Upon this point there are many
theories, some regarding them as the earliest of the Indian tribes.
Others give them a very great age and claim them to belong to
preadamite man. By far the greater number of archaeologists, however,
place their existence at about 2,000 years ago.

In favor of the latter view we may call as evidence the present forest
trees, which, though of great age, still flourish on some of the
ancient remains. On one of the mounds at Marietta, Ohio, there stood a
gigantic tree, which, when cut down, displayed 800 rings of annual
growth. In many other places, trees of the age of 750 years have been
cut, and underneath them evidences of previous forests found. One tree
750 years old was found to have underneath it, on the walls of one of
the forts in Ohio, the cast of another tree of equal size, which would
carry us back at least 1,500 years since those trees began to grow on
those deserted walls of that ancient fortification.

We have some data in the vegetable accumulations in the ancient mining
shafts near Lake Superior, as well as in the vegetable and other
matter deposited in the numerous pits and trenches found among the
works. Though these evidences cannot give the exact time of their
accumulation, yet they give it approximately, by comparison with
similar recent deposits.

There is another still stronger argument in favor of their antiquity,
viz., the decayed condition of the skeletons. The skeletons of the
oldest Indian tribes are comparatively sound while those of the
Mound-builders are much decayed. If they are sound when brought out,
they at once begin to disintegrate in the atmosphere, which is a sure
sign of their antiquity. We know that some skeletons in Europe have
lately been exhumed, which, though buried more than 1,000 years, are
comparatively firm and well-preserved. We are, I think, bound to
ascribe a greater antiquity