Well, the issue with a civilization like Hopewell, which is the same issue for, say, Bronze or Iron age Northern European cultures, is that they aren't really organized at a level of urbanization and hierarchy that would form something playable as a civ. To the degree that any exceptions are made, like with the Turks, or Celts, it is their interactions with other civs that make them a notable addition.
I think perhaps a culture like the Iroquois would be more fitting. They had an agricultural revolution that was allowing for larger populations and then they came into direct contact with Europeans (i.e. other civs). It would be tricky to handle going from the beginning of the tech tree (more or less) to getting the tech for firearms. Maybe a UP that spawns that arquebusier UU that the Native civ has when sharing borders with Europeans. Definitely a bit of a tricky one, but probably doable.