<P> The Open Door Policy is a term in foreign affairs initially used to refer to the United States policy established in the late 19th century and the early 20th century, as enunciated in Secretary of State John Hay's Open Door Note, dated September 6, 1899 and dispatched to the major European powers . The policy proposed to keep China open to trade with all countries on an equal basis, keeping any one power from total control of the country, and calling upon all powers, within their spheres of influence, to refrain from interfering with any treaty port or any vested interest, to permit Chinese authorities to collect tariffs on an equal basis, and to show no favors to their own nationals in the matter of harbor dues or railroad charges . </P> <P> Open Door policy was rooted in the desire of U.S. businesses to trade with Chinese markets, though it also tapped the deep - seated sympathies of those who opposed imperialism, with the policy pledging to protect China's sovereignty and territorial integrity from partition . It had little legal standing, and was mainly used to mediate competing interests of the colonial powers without much meaningful input from the Chinese, creating lingering resentment and causing it to later be seen as a symbol of national humiliation by Chinese historians . </P>

Where did the open door policy take place
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