My kids are learning about pyramids right now. No, not the ones in Egypt. The ones that the Mayans built. We use The Story of the World history books and workbooks which means we learn about history chronologically and are finally moving through North American history.
When Danya went to public school briefly for 5th grade this year we had to do a quick refresher of some main American history info because the public schools teach history egocentrically, which means they start out with a child's family, then their school, city, state, country, and finally world history. Which may be why the rest of the world thinks we are all so self centered. Personally, I don't think you can really understand the uniqueness and exceptionalism of the United States without first having an understanding of all the cultures and governments that came before it.