I read historical fiction as fiction first, and history second. I want a story. It's better if the facts are right, because it's hard to believe in a story if you know things are wrong, and annoying to learn things from a story that turn out to be false, but if the story stops to lecture me about history, then we've left the fiction platform and leaped into the void. Maybe you land somewhere fun, but if you start by cheating your audience it's hard to come back.
Charles Paul May, a writer mainly of nonfiction kids books, seems to understand this important distinction. His Left By Themselves, a book dated 1972 that I bought by mistake at a garage sale a decade ago, is "about" the pernicious Fugitive Slave Law in Iowa in the mid 1800s. But it tells the story of two kids on their own in the snow, who have to keep themselves warm and fed. After figuring out the basic needs, they have to decide whether to trust the bounty hunters who warn them of a ferocious girl-eating slave on the loose in the area, and then they have to decide whether to trust the man they find hiding in the barn. The facts in the book are limited to what the children know, and they know nothing about politics (one of them doesn't know much about farming, either). We aren't even given a date or a place until the end, because the kids aren't reciting the calendar to each other. It's a smooth story that gives a good sense of the place and time, without breaking into mini-lectures. I'll try to pass it on to my third grader, although he may find the brittle pages distracting. This book is just barely younger than his uncle! B
A fun note on titles -- the original name was Stranger in the Storm, which sounds more exciting but doesn't make as much sense since the book is really about the kids on their own. And the manuscript title was Birds Flying High, which is a beautiful reference to the weather lore and the fugitive slave, but doesn't make sense until after you read the book.