Can my spouse and children be included in my E-2 Visa?

Yes, your spouse and unmarried children (20 years old and below) can accompany you or follow to join at a later time as your dependents as Derivative E-2 visa applicants.  There is no requirement that their nationality be the same as your required nationality for the E-2 Treaty Trader Visa.

This is something you should discuss in detail with your US Business immigration lawyer.  The US Business immigration consultancy firm presenting your business would only present the E2-Investor applicant and none of the Derivative E-2 visa applicants.