In the early decades of the colonial period , the development of agricultural colonization system , the private ownership of land , and particularly the thriving of the southern tobacco plantation economy , gave rise to an urgent need of large labor supply 殖民地時期的最初開發(fā)階段,隨著農(nóng)業(yè)殖民制度的實施和土地的私有化,尤其是南部煙草種植園經(jīng)濟(jì)的發(fā)展,長生了對勞動力的巨大需求。