quality:correction, linguistic:voice_change
The Canton System (1757–1842; Chinese: 一口通商; pinyin: Yīkǒu tōngshāng; Jyutping: jat1 hau2 tung1 soeng1, lit. "Single trading relations") served as a means for Qing China to control trade with the West within its own country by focusing all trade on the southern port of Canton (now Guangzhou). The protectionist policy arose in 1757 as a response to a perceived political and commercial threat from abroad on the part of successive Chinese emperors.