Canada and the US are both former British colonies that became independent sovereign states by very different means.
The US became independent through a revolutionary war, whereas Canada became independent by legal means with the willing participation of the UK - basically separation followed by divorce through acts of parliament.
You can end a marriage two ways - separation and divorce, or do what Henry the VIIIth did on a chopping block.
The result of Canadian independence is that the British sovereign (King or Queen) is our symbolic head of state but with no power - purely a figurehead. It is not unlike divorcing someone who still uses their married last name long after the divorce.
Canada is a strong, free, independent and a sovereign state and a valued and respected member of the G7, NATO, the Commonwealth, La Francophonie, the UN etc. We are nobody's 51st state!