Nobody knew Sam was a boy except for him. Sam loves riding his bike and learning about the American Revolution. He is full of laughter and joy. There's just one problem: Sam's family knows him as a girl named Isabel. Sam feels a sense of relief when he finally confides in his annoying but caring sister Maggie, and then his parents, even though it takes them a while to feel comfortable with it. But with lots of love and support, Sam and his family learn and grow through Sam's journey to embrace his true self. In the vein of I Am Jazz by Jessica Herthel, Sam is based on a true story. With a note from the author explaining their family's experience, Sam is an important addition to a list of books that help children and adults discuss gender identity.