American War of Independence (1775-1783) a.k.a. Revolutionary War or American Revolution was a conflict between Great Britain and its thirteen colonies in North America. The colonies ultimately won their independence from the British Empire and established the United States of America.
The Rani visited Earth during the war to collect brain chemicals from humans. (DW: The Mark of the Rani)
The Ninth Doctor claimed to have participated in the Boston Tea Party, a precursor to the actual war. (DW: The Unquiet Dead) The Tenth Doctor later claimed to have helped write the Declaration of Independence convincing the authors to add "the pursuit of happiness" and kept a copy of the first draft in a tuxedo pocket. (DW: The Lazarus Experiment, deleted scene)
Other references
Barbara mentioned the Boston Tea Party in her attempt confuse the Daleks. (DW: The Dalek Invasion of Earth)
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