Caleb Cushing, the first American commissioner to China, concluded the Treaty of Wang Hya (Wanghia) in 1844, which extended to the United States trading privileges equal to those enjoyed by Britain. In particular, this agreement opened certain Chinese Â“treaty portsÂ" and provided Â“extraterritorial statusÂ" to Americans in China.
A treaty port typically was a major ocean or river port city once closed to trade with certain foreign nations, but subsequently opened by treaty. Often these treaty arrangements were forced upon the host nation (China and Japan, for example) and were resented by the residents.
Extraterritorial status allowed certain foreign nationals to remain under the legal control of their home governments. This rendered them exempt from local arrest, lawsuits and taxation. The undercurrent of this idea was that the native population was less civilized than the foreign visitors and could not be trusted to mete out proper justice. Extraterritorial privilege exists today and offers protection to United Nations representatives and foreign diplomats.