Not only the public school system, but universities are failing to teach American history and civics.
Among college seniors, less than half–47.9%–correctly concluded that “We hold these truths to be self evident, that all men are created equal” was from the Declaration of Independence. More than half did not know that the Bill of Rights prohibits the governmental establishment of an official religion, and “55.4 percent could not recognize Yorktown as the battle that brought the American Revolution to an end” (more than one quarter believing that it was the Civil War battle of Gettysburg that had ended the Revolution).
Of course, a lot of these things they should have been taught in high school, but weren’t.