Divisional applications are completely new applications.

If they are based on a PCT, that is, the US national phase application is the parent in the US, then the following applies:

Any documents that can be accessed (because the PCT has been published) do not need to be re-filed again because the USPTO has the documents. More specifically, the priority document(s).

To be included in the filing of the divisional application:

Specification (including the paragraph referring to parent application)
Drawings
IDS
Transmittal