Portal:Indigenous peoples of North America/Selected article/12
The varying cultures collectively called Mound Builders were inhabitants of North America who, during a 5,000-year period, constructed various styles of earthen mounds for religious and ceremonial, burial, and elite residential purposes. These included the Pre-Columbian cultures of the Archaic period; Woodland period (Adena and Hopewell cultures); and Mississippian period; dating from roughly 3400 BCE to the 16th century CE, and living in regions of the Great Lakes, the Ohio River valley, and the Mississippi River valley and its tributary waters. Beginning with the construction of Watson Brake about 3400 BCE in present-day Louisiana, nomadic indigenous peoples started building earthwork mounds in North America nearly 1,000 years before the pyramids were constructed in Egypt.
Since the 19th century, the prevailing scholarly consensus has been that the mounds were constructed by indigenous peoples of the Americas. Sixteenth-century Spanish explorers made contact with natives living in a number of later Mississippian cities, described their cultures, and left artifacts. By the time of United States westward expansion two hundred years later, Native Americans were generally not knowledgeable about the civilizations that produced the mounds. Research and study of these cultures and peoples has been based mostly on archaeology and anthropology.