This is true.
US education used to be extremely patriotic. You could say propagandistic even, about creating a national identity.
This overt plugging of patriotism and national symbols was borrowed from France and Germany in the 19th century.
Whatever its failings, it did succeed in creating a national identity among a diverse people, especially among immigrants.
But in modern times, the last fifty years, its become the policy to do the exact opposite.
For 20 years they’ve been teachibg Howard Zinn’s communist revisionist history of America.