You can legally work in the USA in your own business. Unlike other work permits, here you don’t depend on a sponsor or job offer, you have the control for your Visa.
Once you have an E-2 Visa, it will continue to be renewed indefinitely.
The E-2 Visa allows your spouse (If you are married), to have a work permit and if you have children under 21, they can go to school in the USA.
The E-2 Visa allows you to freely move and travel inside and outside the USA. Your time staying in the USA isn’t limited by the E-2 Visa.