It's 1913 in Oakland, California, and eight-year-old Ellen Jackson has white classmates who bully her and a teacher who believes Black children can't learn. Ellen's mother decides to move the family to Allensworth, the only town in California where Blacks own their own property and govern themselves, free of prejudice.

Oakland is a bustling city with in-door plumbing and gas while in rural Allensworth, Ellen has to lug water from a community well and use the backyard outhouse. But the community members are so helpful and friendly that nobody locks their doors. Ellen's new teacher, Professor William Payne, holds high expectations for his students, and when Ellen falls behind in reading, her tutor is none other than the esteemed Colonel Allensworth.

Ellen makes a new friend, Jasper, and they run wild through the town, climbing the highest trees, until Mama calls Ellen home to play tea party with prissy Pauline. At the Juneteenth festival, Ellen hears an amazing, new music wafting from the hotel piano. It's ragtime! Ellen fingers tingle in her desire to make this upbeat music on her own.

Ellen comes to love Allenworth so much that she wants to make it her forever home. However, trouble is brewing in the little town, and its courageous citizens are uncertain they can hold on to their dream come true.