If you haven’t seen it yet, Newsela.com is a great resource for nonfiction texts (and quizzes). It’s FREE and it presents articles on a range of topics:
War and Peace
You can filter your search by grade level, reading standard, and whether the Newsela folks have designed a quiz for the article.
Even better, the system enables you to convert the articles INSTANTLY into higher or lower Lexiles so you can use them with any grade from 3-12.
Check it out!