The Canadian Charter of Rights and Freedoms was enacted in 1982, so this has nothing to do with the formation of Canada, only this charter and the Constitution.

Before that we had the Bill of Rights (enacted in 1960) and before that we had no formal expression of human rights in Canada.

Forming Canada happened back in 1867.

It is true that the Notwithstanding Clause was negotiated and we likely wouldn’t have the charter without it, but it was very “late” in Canada’s history.