Higher Ground: America's Mound Builders · Episode 1 of 7 · 25 min
Were America's Ancient Mounds Built to Beat the Flood?
The richest farmland in ancient North America was also the deadliest, since the Mississippi silt that grew a bumper corn crop came from floods that could drown the harvest and the seed for next year. Everyone calls the earthen mounds temples and tombs; this series asks whether they were also life rafts. The opener sets up the 5,000-year story and the survival puzzle behind it.
Where it happens
- Mississippi River ValleyFertile and dangerous floodplain where the mounds were built
- Cahokia, Illinois+2 more episodesMississippian city that rose in the American Bottom
- Watson Brake, LouisianaOldest known mound complex in North America
- Poverty Point, Louisiana+3 more episodesLate Archaic earthwork complex
Timeline
- c. 4000-3500 BCEWatson Brake, the oldest known mound building, begins.
- c. 1700-1100 BCEPoverty Point is built by a pre-agricultural society.
- c. 500 BCE-100 CEAdena culture builds earthen burial mounds.
- c. 600-1200 CEA lull in major Mississippi floods lets populations and Cahokia grow.
- c. 1200 CEGreat floods return and Cahokia begins to unravel.
Still debated
Estimates of how many mounds existed, from thousands to tens of thousands, are not a census. Even where a mound kept things dry, that does not prove it was raised for that purpose, and separating deliberate flood-refuge design from incidental benefit is the hardest problem in the case.
