They built them for safety. (Not “Flood Control” or “the king’stent” nor “a place to worship their gods “.)
As recently as the 1927 Mississippi River floods, EVERYBODY across the delta flatlands gathered on the Indian mounds to wait out the rising water for the days it took to for the water to go down.
Yes. The mounds were to build. Took effort.
But. They had no warnings from upstream. No warnings of floods of any kind. Once the water began rising, the Indians could only evacuate to higher ground. And higher ground was 4 days travel away.
Build a mound using mud, dirt. And slaves.
Next year, next flood five years later?
Your tribe is the only one surviving.
You get all of their land.
Build a mound too low? You tribe dies. You die.
And that technique works in any flat valley, not only the hundreds of miles of the lower Mississippi.
