My schooling in the 70s and 80s was all about how great Columbus was and how helpful and gracious native people were to the people who came on the Mayflower. There might have been a paragraph about the Trail of Tears. Manifest Destiny was taught as a good thing.

The fact is that there's limited space in general [nation] history books, and in the US at least, the fight for that space is heavily influenced by national/civic pride and American Exceptionalism.