May not want to know this but ill leave it in case someone else does.

They all need to be taught for sure. Just not sure about the Pledge being said every morning in schools. The history of the Pledge is iffy. Was written by Socialist Francis Bellamy who wanted men drafted into the country's "industrial army" and advocated for the State to assign jobs while everyone earned the same pay. Bellamy wrote the book "Jesus the Socialist" and was removed from his church while as a Pastor for his Socialist views.

Others believe the Pledge was a way to promote Federalism and reduce the mindset that States had powers separate from the Federal Government. Since the country was "one nation" and "indivisible", it promoted federalized and socialistic tendencies and was a way to prevent states from being independent and succeeding from the Union again.

While the pledge may seem as though its patriotic, others would argue that its way to promote authortarian governments.

Side note: Prior to the Civil War citizens identified with their state rather than as American: Georgian, Virginian etc. rather than American.