Of course, the content of the lesson plan can be controversial.
https://www.washingtonpost.com/local/education/150-years-later-schools-are-still-a-battlefield-for-interpreting-civil-war/2015/07/05/e8fbd57e-2001-11e5-bf41-c23f5d3face1_story.html
https://www.theguardian.com/world/2010/may/16/texas-schools-rewrites-us-history
For comparison, here is what the state of Texas wrote in 1861:
https://www.civilwar.org/learn/primary-sources/declaration-causes-seceding-states#Texas