Unita Blackwell, who was born in a sharecropper’s shack in Mississippi in the depths of the Depression, grew up having no idea what it meant to vote. She did not even know the word.

Then, in 1964, civil rights activists arrived in her corner of the South. They told her about voting, she said years later — that it could put food on the table and help her find decent housing, “that the vote was the key, that you would have the say-so and that you could get those things into your community.”

But she also learned that just trying to register to vote in Mississippi could get a black person killed.

These realizations marked her political awakening, prompting her to lead voter registration drives and devote herself to the civil rights movement.