Name given to Native Americans who built numerous earth mounds in what is now the eastern and central parts of the United States, particularly in the Ohio and Mississippi river valleys.

Archaeological research in the late 19th century clearly indicated that the people who built these mounds lived at various periods of time and were the ancestors of the Native Americans found by Europeans in the same region. It is likely that the mounds were built over a span of several thousand years by groups of people who were economically similar, probably farmers living in permanent villages.

Early European settlers in the area, however, attributed the mounds to a hypothetical race of people antedating the Native Americans. The myth of a pre-Native American mound-building people persisted for many years.

The size, shape, and purpose of these mounds varied from place to place. The largest was the Cahokia Mound found in Illinois. Conical and pyramid shapes were common.

Those in eastern North America served a variety of purposes.

Some, known as midden mounds, resulted from hundreds of years of habitation and the accretion of garbage and other residential debris; these probably date from about 1000 BC.

Other mounds were built as funerary monuments. Some burial mounds, dating from 500 BC and later, had a central chamber that contained the remains of notable personages.

Others were cemetery areas for less important people.

After AD 700, particularly in the upper Midwest, many mounds were built in the form of animal effigies.

Platform mounds, originally constructed as bases for public buildings, houses of leaders, and temples, date from the period after AD800. Spaced around a plaza, they formed the central portions of important communities. Such mounds were being built by various indigenous groups at the time of European contact with eastern North America.

Early French settlers witnessed the use of mounds for public buildings and burials by the Natchez.

Mound building ceased shortly after European contact, as Native American cultures declined under the impact of epidemics and cultural change.

The Serpent Mound twists to a length of 411 m (1348 ft) near the town of Peebles in southern Ohio. It is believed to have been built by the Adena, whose culture flourished in the first millennium BC. Archaeologists are unsure as to the purpose of this mound. Mark C. Burnett/Photo Researchers, Inc.

"Mound Builders," Microsoft® Encarta® Online Encyclopedia 2000 http://encarta.msn.com © 1997-2000 Microsoft Corporation. All rights reserved.