The best middle-grade books are the ones that help to open up the world for young readers, whether by providing models for them to emulate, giving them insight into the experiences of another, or offering them a view they’ve never seen before. Each book becomes a brick in an edifice of understanding, and this year’s best middle-grade books are exceptionally sturdy ones.

Alex Gino’s eponymous, transgender protagonist, George, knows that she’s a girl, but she’s all alone in that knowledge. With a direct and ingenuous third-person narration and the critical, consistent use of the feminine pronoun, Gino provides a model of simple dignity for transgender and cisgender readers alike. In stark contrast, Ronald Kidd’s Billie, protagonist of Night on Fire, has been supremely comfortable inside herself for 13 years, until the Freedom Riders cause her to understand the unearned privilege she’s lived with just because she’s white—and the corresponding hardship that comes with simply being born black.

Ava, in Kimberly Brubaker Bradley’s The War That Saved My Life, knows hardship all too well: thanks to her untreated clubfoot, she can barely walk, and her cruel mother has kept her prisoner in their tiny flat. Readers will feel relief when she and her brother are evacuated to the countryside during the Blitz, opening her world in unimaginable ways. Joseph M. Marshall III’s Jimmy, unlike Ava, has an abundantly loving family, but he’s also got genes that make him look like a white boy and feel out of place on his Lakota reservation. His grandfather takes him on a road trip In the Footsteps of Crazy Horse, allowing him and readers to see some of the complexity of U.S. history.

These and other novels, together with the early readers, graphic novels, books of poetry, and nonfiction that combine to make up this year’s best books for middle-graders, give kids one solid foundation. Vicky Smith is the children’s & teen editor.