Answer
- As burial mounds
- As temple platforms
- As defensive structures
Step-by-step explanation
Earthworks is the process of soil disturbance in any means which includes excavation, digging tunnels and the construction/reconstruction of any track, embankment, or drainage channel. In eastern North America cultures were built by earthworks for the purposes of burial mounds which were used as graves , temple platforms where different groups of people went for worship, they were also built by earth-workers and defensive structures. These allowed people to be able to defend themselves whenever war broke.