American War of Independence

American War of Independence was a conflict between Great Britain and thirteen of its 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)

Other references

 * Barbara mentioned the Boston Tea Party in her attempt to confuse the Daleks. (DW: The Dalek Invasion of Earth)