Before They Let Us Play Vol. 3 — Cagers, Rens, and Trotters: Basketball's Separate Game (Kid-Friendly Edition — Free Sample, Chapter 1)
Read Chapter 1 free: "The Early Game and the Color Line" — the whole chapter, exactly as it prints, sources and method note included. Includes both the interactive HTML sample and a PDF sample (device read-aloud only; recorded narration by Marcus is a feature of the full Interactive Edition). The full Interactive Edition adds the remaining five chapters, recorded narration by Marcus (23.81 minutes), the timeline, and the educator quiz.
Free ($0) on Payhip and Gumroad; $0.99 on Etsy. Edition: Kid-Friendly Edition. They built their own game. Then they took the whole game.