Textbooks suck

Yesterday I have overheard a girl in my class talk about how different Chicago is compared to California. She mentioned that while in school in Chicago, the history textbooks go into depth about themes such as the black panthers and movement. While in California, the textbooks barely touch base on the theme about the black panthers. It's weird to think that even in states in the U.S they  have differences on textbooks and what they teach. I honestly think they should all contain the same amount of material because they are living out important history that is important to learn.  For example, in history the teachers don't talk about the Mexican movement and I wasn't to be in global, I would've never learned about the movement because the U.S textbooks exclude that thinking it's not important to its history. Perfervidly because they're ashamed of proving the people the resources needed.