Though born in Queens, McGoohan got his start in the theatre in England, eventually making his way to British television, where The Prisoner was created as a miniseries in 1967. It's a strange, almost un-pin-downable kind of series—it's simultaneously about individuality and unanimity, the dark shadows of government, penny farthing bicycles, and giant bubbles that come out of the sea and kill people (so brilliantly parodied on The Simpsons. Poor Moleman.) McGoohan played Number 6, the otherwise-unnamed ex-spy who finds himself a prisoner in a strange Village and continuously tries to buck the system and escape.
McGoohan, who had previously turned down offers to play James Bond, went on to other cultish parts—in Escape From Alcatraz, Scanners, and The Phantom—but in the end was mostly known for the seventeen episodes he spent trapped in the ominous Village. I guess he's free now, killer bubbles be damned.
You can watch every bizarre episode of The Prisoner here.