Some friends told us about another author who we’ve come to enjoy — Piet Prins. His books aren’t typically available in libraries, but can often be found used. He has a great series on the Dutch Resistance during WWII. His books are always accurate and appropriate for all ages. My kids were 6-12 when we read these and they all begged for more. He also has a series about a dog, Scout, and another series about an Eskimo boy. All wonderful!!
I agree with most of the books already mentioned as well, but if someone is looking for something new, I highly recommend these.