Rep. John Lewis’s story as a civil-rights leader is so big, even three graphic novels couldn’t tell it all.

“March,” the trilogy retracing African-Americans’ fight for equality through Mr. Lewis’s eyes, topped best seller lists and in 2016 won a National Book Award. “Run,” its first volume slated for release in August, continues the story, following him through the backlash against the civil-rights movement and the tensions that helped splinter it, putting him on the path that would ultimately lead him to Congress.

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