[Rekksu]

that's only specifically the first 10 amendments, which are generally referred to as the bill of rights as they were added to the constitution when it was ratified and cover most basic freedoms so they're taught in school

other rights-granting amendments are the post civil war ones which are slightly less well known but also covered in school

[Gigachad]

Nah I often see people talking about stuff like prop <some number> expecting everyone to know what that refers to.

[midoridensha]

Most Americans won't know those, because those are state-specific (usually for California; most states don't even have Propositions that citizens can vote on).

Every American knows what the 1st Amendment is, by contrast.