I apologise that I don't have an exact cite at hand, but I recall learning about things such as inter-operability agreements (for provincial/territorial/state drivers' licenses) that apply across the USA and Canada.
And those documents in turn rely on foundational ID documents such as #BirthCertificates, #CitizenshipCertificates, etc.
IIRC this is a treaty-level agreement so not simple to ignore.