It is a part of a Treaty of Commerce, where members of this treaty obtain the right to work and live in the USA.
The general qualification of a treaty investor:
• Be a national of country which US keeps a Treaty of Commerce and navigation
• Invest in US enterprise (sufficient capital – depending on the business)
• Investor can control their investment, usually 50% ownership of the business in US
• The enterprise has to be active
• Treaty investors will only need to create two to three jobs within 24 months
• If your country is not part of the E-2 treaty you can invest in a third country (part of E-2 treaty) and apply for a citizenship through an approved-government agent. Once you have had your citizenship for five (5) years, you will then be able to apply for the E-2 visa.