believed, that all the mounds had a similar origin.

Lewis and Clarke mention not only the erection of a mound over a
modern chief, but also numerous earthworks, including mounds,
which were known to be the work of contemporaneous Indians.
[Footnote: Travels, Dublin ed., 1817, pp. 30, 31, 55, 67, 115,
117, 122-125, etc.]

L. V. Bierce [Footnote: Historical Reminiscences of Summit County,
Ohio, p. 128.] states that when Nicksaw, an old Wyandotte Indian
of Summit County, was killed, "the Indians buried him on the
ground where he fell, and according to their custom raised a mound
over him to commemorate the place and circumstances of his death.
His grave is yet to be seen."

Another writer says: "It is related by intelligent Indian traders
that a custom once prevailed among certain tribes, on the burial
of a chief or brave of distinction, to consider his grave as
entitled to the tribute of a portion of earth from each passer-by,
which the traveler sedulously carried with him on his journey.
Hence the first grave formed a nucleus around which, in the
accumulation of the accustomed tributes thus paid, a mound was
soon formed." [Footnote: Smith's History of Wisconsin, vol. 3,
1834, p. 245.]

The same author says [Footnote: Ibid., p. 262.] the tumulus at the
Great Butte des Morts (Great Hill of the Dead) was raised over the
bones of Outagami (Fox Indian) warriors slain in battle with the
French in 1706.