In what parts of north america did the mound builders live?

Mound Builders, in North American prehistory, was the designation granted to those people who raised mounds in a large field from the Mississippi River to the Appalachian Mts and Great Lakes to the Gulf of Mexico. The most prominent congregations of mounds are recognized in the Ohio plains. The hills matched 65 ft. in height and were fashioned solely by standard labor. Mound builders existed in dome-shaped houses constructed with pole walls and thatched rooftops.

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explanation:

the second significant cause of the great migration was the desire of black southerners to escape segregation, known euphemistically as jim crow. rural african american southerners believed that segregation - and racism and prejudice against blacks - was significantly less intense in the north.