What is the history of US-Canada independence?

Answer 1

It's not clear whether you are thinking of Canada's independence from the US (or the other way around). But Canada never was part or a colony of the US. As it is, Canada simply established itself as a nation independent from Britain in 1919 by joining the League of Nations as a sovereign country without Britain's involvement. This de facto independence was confirmed by the British Government's Statute of Westminster in 1932. In 1982 the last small remnants of British influence over Canada were removed through the Canada Act of 1982.

The Queen is still Canada's Head of State, but her role there - as represented by her Governor-General - is only ceremonial. The Governor is always a Canadian citizen and appointed by the Queen as proposed by the Canadian Government.

The US declared itself independent from Britain in 1776. Britain formally recognized the USA's independence in the peace treaty of 1783.