 For the countries in North America and Australasia, great numbers of laborers were also needed in the dangerous tasks of gold mining and railway construction.Widespread famine in Guangdong impelled many Cantonese to work in these countries to improve the living conditions of their relatives.Some overseas Chinese were sold to South America during the Punti-Hakka Clan Wars (1855–1867) in the Pearl River Delta in Guangdong.