There are 8 main requirements to qualify for an E-2 visa:
Duration of Stay
E-2 status is valid for two year increments, with an extension of two years at each entry. Visa stamps are valid for up to five years, depending on country of nationality and visa reciprocity.
Dependents
E-2 visa applicants are permitted to include spouses and children as dependents in E-2D status. Once in the U.S., an E-2D visa holding spouse is eligible to work pursuant to status.