554 THE MOUNDS OF THE MISSISSIPPI VALLEY. 
exception, can be proven to have been at some time the seats of mound- 
building Indians, and because never, so far as we know, have they 
been held even temporarily by any other race of people previous to the 
arrival of the whites. 
In pursuing this branch of our inquiry the only method open to us 
is to proceed by comparison. For obvious reasons we can never know 
the particular individuals by whom these works were erected, nor cai 
we, except in a few cases, even hope to do more than approximate the 
time when they were built. All that can be accomplished in the pres- 
ent state of our knowledge is to show by a comparison of these re- 
mains with similar works that are known to have been erected by the 
modern Indians that there are no such differences between them as 
would authorize the inference that they were built by different peo- 
ples, or by the same people in different stages of civilization. 
To institute a comparison of this character seems like a very simple 
matter, and it would be so if there were any way of establishing a hard 
and fast line of demarcation between the works of the Indians and those 
of the so-called mound-builders. Unfortunately however or perhaps 
it might be more correct for me to say fortunately, nothing of the kind 
‘an be done; for though, as a matter of fact, the mounds and earth- 
works of the Mississippi Valley do vary indefinitely in size, shape, loca- 
tion, grouping, and possibly in many other respects, yet these are all 
differences of degree and not of kind; and however great the distance 
between the extremes in any one of these particulars, it is not of such 
a radical character as to indicate a difference in the civilization of the 
people who constructed the works. Given time and an indefinite sup- 
ply of laborers, and there is no reason why the people who built one 
might not have built any and all of them. The simple manual labor 
necessary to their construction was essentially the same in every case, 
the only question being as to the amount. That this is so is evident 
from the fact that when considered solely with reference to the kind 
and amount of this labor, these works are found to grade into each 
other by such imperceptible stages that admitting them to have been 
erected by different peoples, it is impossible to say where the work of 
one ended and that of the other began. This statement has I know 
met with more or less opposition, and it is quite likely that in the 
future, as in the past, we shall be told of the existence of some line of 
demarcation between them, though it is possible that the attempt to 
fix and define it will not meet with any better success than has crowned 
former efforts in the same direction. Size, shape, and probable use 
have at different times been thought to furnish a key to the mystery; 
and either singly or together they are still occasionally made to do 
duty in this capacity; but with all due deference to those who so per- 
tinaciously seek for differences where none exist, it may be said, without 
fear of successful contradiction, that thus far not one of these so-called 
distinguishing features has been able to stand the test of intelligent 
