Generally speaking, a polis of ancient Greece was a "City State," in which there was a great deal of autonomy and self-governance, which was a goal of many Greek philosophers of the day.
How does Vaughn depict power relations and social hierarchy among the Powhatans? Vaughn depicts Powhatan society as one strictly divided by social hierarchy. Most of the Powhatans sit in mass along the sides of the scene and their features are virtually indistinguishable.
Horizontal integration is the acquisition of a business operating at the same level of the value chain in the same industry. Hope this helps
