I recommend Lies My Teacher Told Me Textbook by James W. Loewen because it critiques the textbook industry’s whitewashing of US history. But tbh, detecting truth and accuracy might require a good understanding of rhetoric and logical fallacies (or read up on the philosophy of skepticism first). Most books on US history use primary sources, but the author’s synthesis and selection of those sources is what might get called out as inaccurate or opinionated.

The other issue with “unbias” or “apolitical” history (and others may disagree) is that it does not exist. Reality is socially constructed. The hard sciences can sometimes avoid this problem, but the social sciences cannot. Even if all political opinions are removed from the description of a historical event, the story will always be limited. Certain details will be selected to represent the “true” or “accurate” story. And certain details will be left out. That fact alone no author can get away from. The US has a long history and less than 1% of it could ever be described in a single book.

I recommend learners view “bias” as something they are aware of, not something that can ever be gotten rid of. Perspectives will always be limited. Will the bias in a US history book be towards.....women’s rights, the expansion of the railroad, immigrant experience, historiography, agriculture, military conflict, presidents, food and drink, fashion styles, counter culture, the east, the west, suffrage, consumerism, the frontier, domestic policy, international policy, the working class, titans of industry, children’s rights, education movement, constitutional law, etc etc etc? If any single book tried to do justice to any of these perspectives it would be spread so thin that......well that’s why k12 textbooks don’t teach you anything in much detail.

I recommend picking a topic of interest more narrowly defined than just “US History,” then identify the bias (or limited perspective) based on the author’s background and scope of the book. Next, read a book on the same topic but with the opposite bias. This is roughly know an Hegelian dialectic: thesis + antithesis = a new understanding of “truth.”