Question

When and how did Canada eventually gain its independence from Great Britain?

Answer 1

July 1st 1867 Canada gained independence from great Britain

Explanation:

Canada passed the British North American Act, which allowed Canada to become a self-governing entity within the empire

Answer 2

It was a 3 step process and is still not quite complete.

Explanation:

In 1867 Canada was made a Dominion. In 1931 The Statute of Westminster gave Canada and other members of the Commonwealth a greater degree of Autonomy. In 1982 the Constitution was repatriated from Britain. Final ruling on Constitutional matters previously had to go to the United Kingdom Privy Council. Unfortunately Quebec did not ratify this Constitution so there is still some matters in doubt to this day.

But yes July 1st, 1867 Canada was considered independent.

For more on the lead up to the Statute of Westminster see: https://en.wikipedia.org/wiki/King%E2%80%93Byng_affair