A Republican majority on the elected Texas State Board of Education has approved new standards for textbooks and school curricula that are so contentious that a campaign has been launched to remove them from office in the autumn.
Their revisions include playing down the fact that some of the nation's founding statesmen owned slaves, changing the name of the transatlantic slave trade to the "Atlantic triangular trade" and listing negative consequences of affirmative-action policies meant to address previous racial imbalances. They are also seeking to de-emphasise the civil rights movement and the brutality of the Ku Klux Klan.
The word "capitalism" is to be replaced with "free enterprise", and teachers are also being told to downplay the separation of church and state - and the man who championed that idea, Thomas Jefferson - while stressing that Jefferson and the others who founded this secular nation were driven by Christian principles.
Because heavily populated Texas buys textbooks for 4.8 million students, its influence on publishers extends beyond its borders. Independent groups affiliated with the Tea Party movement are now calling for the same changes to history curricula in Georgia and Tennessee.
"There has developed on the Right this fevered myth that public schools and textbooks and textbook publishers are all out to demonise the United States and important historical figures. I call it a fevered myth because it's simply not true," says Dan Quinn, a former textbook editor and communications director of the Texas Freedom Network, which is campaigning for voters to dump the conservative bloc on the education board in an election that promises to be almost as polarising as the presidential race.
Those proposing changes to the curricula, however, argue that history must be taught in the context of the times rather than through the prism of contemporary values. "What you want to do is look at the things that happened in light of what the people at the time were experiencing and their values," said Hal Rounds, attorney, Tea Party member and spokesman for the group pushing revisions to the way that history is taught in Tennessee.
At the time that the United States was founded, Mr Rounds said: "The whole world was pretty much a pattern of master-servant relationships, whether it was serfdom or slavery. Everybody had a boss who had arbitrary control over them.
"What our founders invented was that each man should be his own master. And they are coming out of a social organisation where they had had obedience to the king, which was a pretty dramatic arbitrary control system. So that was a radical thought for the times."
However, Mr Rounds' Tennessee campaign for revising textbooks is perhaps less nuanced. "No portrayal of minority experience in the history which actually occurred shall obscure the experience or contributions of the founding fathers, or the majority of citizens, including those who reached positions of leadership," it says.
But Gary Bledsoe, president of the Texas chapter of the National Association for the Advancement of Colored People, said: "Teaching the benevolent aspects of slavery does even further harm to our ancestors who were unfortunately enslaved."
Critics come forth
Critics of the textbook revisions include the committee of nine teachers and university academics appointed, and then largely ignored, by the Texas State Board of Education.
They had been asked to propose a new curriculum free of political bias. The conservative board members' changes to that proposed curriculum "reflect their lack of historic knowledge and their failure to listen to the appointed citizen review committees", the committee wrote.