American Institute in Taiwan in the context of Congressional oversight

The United States ambassador to China is the chief United States diplomat to the People's Republic of China. The United States has sent diplomatic representatives to China since 1844, when Caleb Cushing, as commissioner, negotiated the Treaty of Wanghia. Commissioners represented the United States in China from 1844 to 1857. Until 1898, China did not have a system in place for the Emperor to accept the Letters of Credence of foreign representatives. From 1858 to 1935, the United States representative in China was formally Envoy Extraordinary and Minister Plenipotentiary to China. The American legation in Nanjing was upgraded to an embassy in 1935 and the Envoy was promoted to Ambassador Extraordinary and Plenipotentiary.

During the republican era, the United States recognized the Beiyang Government in Beijing from 1912 to 1928 and the Nationalist Government in Nanjing (and Chongqing from 1937 to 1945) from 1928 onwards. After the Communist Party established the People's Republic of China in mainland China in 1949 and the Kuomintang moved the Republic of China government from Nanjing to Taipei of Taiwan, the United States continued to recognize the Republic of China as the legitimate Chinese government and maintained its embassy in Taiwan. However, in 1973, the United States established a Liaison Office in Beijing to represent its interests in mainland China. In 1976, the Chief of the Liaison Office was promoted to the rank of ambassador. In December 1978, the United States severed official relations with the Republic of China and in January 1979, established formal relations with the People's Republic of China. The United States Liaison Office in Beijing was upgraded to an embassy on March 1, 1979. The American Institute in Taiwan was established in 1979 to serve as the unofficial United States representative to Taiwan, with the director of its Taipei Office taking the role of a de facto ambassador.