> Alberta was created within Canada by subdividing what was then the Northwest Territories, already part of Canada.
The same is true of the majority of the US states. The original 13 colonies and Texas and Florida (and maybe a few more?) had some preexisting status, but the rest were created out of Federal territories.
True, but they were then granted the same sovereign status as the original 13 colonies, and Texas, and Florida.
One example of the difference is that in the US, there's state and federal criminal law, and state authorities draw their legitimacy from the state constitution. The criminal code in Canada is entirely federal.
Territories were not merely cut up into states. They were cut up into states in a way to ensure there would be an equal number of free states and slave states. Certain states might not have existed if not for these considerations.
The same is true of the majority of the US states. The original 13 colonies and Texas and Florida (and maybe a few more?) had some preexisting status, but the rest were created out of Federal territories.