Answer:
Opium Wars.
Step-by-step explanation:
The Opium Wars opened China specifically to trade with not only Europe, but also America. Before the Opium Wars, Britain was selling large amounts of Opium drugs to China in an effort to milk the cash cow, leading to the Emperor declaring Opium's as contraband. With this action, Britain, France, United States, and other European countries attacked and brought the Chinese government to the table, leading to China giving up large areas of their coasts to "spheres of influence", in which each victor country took a part to influence for themselves.
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