■' Cahokia Mound. The largest prehis- 
toric artificial earthwork in the United 
States, situated in Madison co., 111., in 
what is known as the American bottom, 
about 6 m. e. of St Louis, Mo., and in 
plain view of the railroads entering that 
city from the e. Before their partial 
destruction by the plow the principal 
mound was surrounded by an extensive 
mound group, numbering, according to 
Brackenridge (Views La., 187, 1814), who 
visited the place in 1811, “45 mounds 
or pyramids, besides a great number of 
small artificial elevations.” The name 
Cahokia is that 
of a tribe which 
formerly occu- 
pied a neighbor- 
ing village of the 
same name. In 
form the tumu- 
lus is a quad- 
rangular pyra- 
mid with an 
apron, or terrace, 
extending from 
the s. side. The 
dimensions as 
given by Mc- 
Adams (Antiq. 
of Cahokia or 
Monk’s Mound CAH0KIA mound, ILLINOIS; height, as measured by mcadams, 99 ft.; 
O inno\ ’ GREATEST LENGTH, 998 FT. 
mound would form a wall of the same 
base and height exceeding 17 m. in 
length, or more than five times the length 
of the wall of Ft Ancient, and would 
have required, according to the usual 
method of calculation, the labor of 1,000 
persons for 4f years, with the means 
that prehistoric Indians had at hand. 
The places from which the earth was 
taken are apparent from the depressions 
surrounding the Cahokia mound. In 
1811, when visited by Brackenridge, the 
largest terrace was used by a colony of 
Trappists (whence sometimes the name 
Monk’s Mound) , who resided in several 
small cabins on one of the smaller 
mounds, which latter was cultivated as 
a kitchen garden. See Brackenridge, 
op. cit. ; Bushnell, Cahokia and Surround- 
ing Mound Group, Peabody Mus. Publ., 
1904; Conant, Footprints of Vanished 
Races, 1879; McAdams (1) Records of 
Ancient Races, 1887, (2) Antiquities of 
Cahokia, or 
Monk’s Mound, 
1883. (c. t. ) 
-L KJKJU J dAV-/ tUO 
follows: The base n. and s., 998 ft.; e. to 
w., 721 ft. ; height, 99 ft. ; height of lower 
terrace, 30 ft. ; outward extent of terrace 
about 200 ft.; width about 500 ft. The 
area of the base of the mound is estimated 
at about 16 acres. On the w. side, some 30 
ft. above the first terrace, there was a sec- 
ond slight terrace, now scarcely distin- 
guishable. Patrick, who studied the 
mound and its surroundings, and prepared 
a model which was cast in iron (now in the 
Peabody Museum at Cambridge, Mass.), 
represented a small level area or terrace 
some 3 or 4 ft. below the level top. Omit- 
ting the lower terrace and counting the 
diameters of the base as 721 and 798 ft., 
and the height as 99 ft., without regard to 
the upper level, the contents somewhat 
exceed 18,690,000 cu. ft. Adding the 
terrace, 3,000,000 cu. ft., the total con- 
tents amount to 21,690,000 cu. ft. The 
wall of Ft Ancient, Ohio, has been fre- 
quently referred to as one of the most 
extensive ancient works of the United 
States, yet the contents of the Cahokia 
