You’re right; the Gov is technically correct. Indentured servitude was the predominate source of imported labor in early Virginia. As I understand it, it worked but not all that well (indentured laborers could simple walk off a bit too easily and then the planter was faced with the problem of importing more and seeing to their “seasoning”.
Importation of black slaves really took off with the growth of rice farming (mainly in the Carolina coastal region and mainly by British and French) which required a large workforce to build and maintain the irrigation involved. This vastly increased with the spread to the south of cotton growing.
You skipped over tobacco.
Tobacco was the huge crop before cotton.