The Black Card started out as an urban legend in the early 1980s circa 1984. It was alleged by that American Express handed out a high end ID with unusual privileges. This rumor is corroborated by a Wall Street Journal article written in 1988, despite the fact that American Express continually declined the rumor as true.
From WSJ: Suppose, for example, on a 3-o’clock-in-the-morning whim, you decided to book a round-the-world trip; American Express would accommodate you with a travel service staffed 24 hours a day. In the market for a red 1965 Ferrari? If you were a black-card holder, American Express would kick tires in the world’s fanciest used-car lots. If you remembered in Singapore that you had left your favorite suit in a Hong Kong penthouse, the company would arrange to fetch it. (full 1988 WSJ Black Card Article Here)
On October 14, 1999, publicly launched the American Express Centurion Card aka The Black Card, see original press release here. Doug Smith, director of American Express Europe said:”There had been rumors going around that we had this ultra-exclusive black card for elite customers… It wasn’t true, but we decided to capitalize on the idea anyway. So far we’ve had a customer buy a Bentley and another charter a jet.”
In 2004 in Europe and 2006 in the US the Centurion Card was switched over to Titanium from Plastic.
In 2006 American Express also raised the eligibility requirement from 150,000 annual spend to 250,000 annual spend.