Long before the Egyptians began building pyramids, North
Americans were erecting massive earthworks, archaeological
A team of researchers reported in Friday's edition of the
journal Science the discovery of the oldest reliably dated
human-made structure in North America, a 5,400-year-old earthen
mound at Watson Brake, La., which is almost 2,000 years older than
The circular mound, about two stories tall, forms an enclosure
nearly 300 yards in diameter, but its purpose is not clear.
The discovery of this and other mounds in Louisiana and Florida
suggest that the earliest Americans - long thought to be simple
hunter-gatherers - were actually capable of organizing and
executing large civil engineering projects, the team reports.
Mike Russo, a National Park Service archaeologist, said: "We
once thought society was very slow to develop in North America. In
fact, there were numerous societies here capable of monumental
architecture much earlier than we had ever expected."
And what is becoming clear, he added, is that some of these
early groups had a relatively comfortable existence, with ample
supplies of food and enough time on their hands to undertake
massive public works projects.
Such societies had to have a rich biological niche to support
relatively large populations without the benefit of agriculture, he
said, but they also had to have "social conventions that would
allow them to do something innovative, like build mounds."
Although archaeologists have often tended to ignore them, and
the general public is often unaware of their existence, thousands
of human-made mounds dot the East and Midwest. Shaped like massive
serpents, giant cones and square platforms, these 2,000- to
3,000-year-old mounds in some cases have been shown to have served
as ceremonial centers, slaughterhouses and residential sites.
Older Than Cahokia
Cahokia Mounds near Collinsville are modern, by contrast,
having been built between 600 and 1,000 years ago, according to
Bill Iseminger, a spokesman for the state historic site.
He explained that the St. Louis area was inhabited by hunters
and gatherers 5,400 years ago but that they had not advanced to
Cahokia Mounds, he said, developed to be a major city that once
held 10,000 to 20,000 residents. That is a downward revision from
earlier guesses of as many as 40,000. Archaeologists call the
inhabitants Mississippians, for lack of knowing what they called
More mounds are being found in Louisiana and Florida, where the
rich mixture of wildlife and marine life from bays and rivers was
capable of sup porting larger indigenous populations. …