Mr. Jackson arrived in New York on Halloween night 1976, and for several years made his way as a theater actor, rolling with a crew that would become the defining faces of a generation: Denzel Washington, Wesley Snipes, Alfre Woodard. “We pooled our money and ate together, partied together on weekends, went to the same unemployment office,” he recalled.

He was a regular at the Public Theater, later did stand-in work for Bill Cosby on three seasons of “The Cosby Show,” and was eventually recruited to, as he called it, “Spike Lee summer camp.”

Since then, he has worked constantly, and feverishly, partly because of a long-ago conversation with a casting director who said that he frowned on actors who take months off between roles. Mr. Jackson makes no distinction between big films and small ones, animation and live action, movies and commercials. He speaks passionately about his Capital One ads. “I remember sitting at home and watching that commercial and at the end of it saying to myself: ‘What’s in your wallet? What’s in your wallet? What’sinyourwallet? How would I say that?’” he said. “So when it came up, it wasn’t a question to me.”

Besides, he pointed out, he had done Barclays Bank commercials in England more than a decade ago. He texted his assistant, Volney, asking him to bring over a laptop and call them up on YouTube. “These are awesome,” Mr. Jackson said, clicking through and finding one that looked to have been filmed in a monsoon. “This one’s crazy good. I was miserable.”

The thread that ties all of his work is unbreakable, and highly particular. “Samuel music,” is how Raoul Peck, the director of the James Baldwin documentary, “I Am Not Your Negro,” which is narrated by Mr. Jackson, described it. “His tone, the sounds he makes, the different accents, the different intensity.”

Mr. Jackson recorded all of his parts for that film in one day in Bulgaria, where he was filming “The Hitman’s Bodyguard.”