18世紀末至19世紀初，從事廣州貿易的美國商人聚居澳門，使之成為中美經濟、文 化最早的交匯地。隨着19世紀美國在東亞的經濟勢力迅速擴張，對華貿易商人形成了一個強大 的利益集團，他們最終促使美國政府與中國簽訂通商條約，建立外交關係，以保障他們的利權。 回顧澳門在廣州對外貿易體系中的地位，以及美國商人、傳教士在澳門地區的活動，闡述澳門及 望廈地區在19世紀中葉的國際地位問題，可凸顯兩國選擇在澳門半島談判和簽訂第一個中美條 約的因由，而從國際法和美國外交史的角度，亦可重新探討《望廈條約》的歷史意義以及美國對華政策的起源。

During the late eighteenth and early nineteenth centuries, American merchants in the Canton trade settled in Macau and it became the first Sino-American meeting place for economic and cultural exchanges. With America ’s rapid economic expansion in East Asia in the nineteenth century, the China traders formed a powerful interest group. They ultimately persuaded the American government to conclude a commercial treaty and establish diplomatic relations with China in order to guarantee their interests and rights in the China market. This article first reviews Macau ’s position in the Canton trading system and examines the activities of American merchants and missionaries in Macau. It then discusses the international status of Macau and the Wangxia area in the midnineteenth century and analyzes why the two countries opted to negotiate the first Sino-American treaty in the Macau peninsula. From the perspectives of international law and American diplomatic history, it also revisits the historical significance of the Treaty of Wangxia and contributes to the recent debate on the origins of American China policy.