If the foreign investor is already in the United States in valid status (visitor or other legal status), then s/he files an E-2 petition and a letter in support along with required documentation with the USCIS Service Center and may begin employment upon issuance of the USCIS approval.
The foreign investor may instead apply for an E-2 visa directly with the United States embassy or consulate. The foreign investor does not file an E-2 petition but must provide a letter in support along with required documentation. Again, the foreign investor completes form DS-160 online and the United States consulate conducts an interview and issues the foreign investor an E-2 visa valid for 5 years. The United States consulate also issues an E-2 visa to any spouse and minor (under 21 and unmarried) child(ren) of the foreign investor. Upon issuance of the E-2 visas, the foreign investor, spouse and any child(ren) may enter the United States.