Black Box was created as analog of Green Lantern Alan Scott by Mark Millar to be used during the River Run arc in Millar's Swamp Thing run. Set in a metafiction inside the story, the character was an stand-in for the golden age Green Lantern because of the Vertigo-mainstream DC characters restriction working on that time. Millar also would use other analogs for DC characters such as the Traveller (stand-in for Phantom Stranger) and the Word (an Spectre replacement).
Laurence Cooper became the Black Box when a mysterious black box materialized in his cellar. Using the box as a power source and channeling in a power staff as a purple plasma, Cooper fought against the forces of darkness even beyond which includes Solomon Grundy.
Twenty years later, Cooper prime time has passed and now he lives a retired live along with his wife, Anna, in the city of Moline, mourning his lost son, Michael, a kid born with a neurological disease and who was suppously kidnapped by unknown persons
. One last adventure would put him against a resurrected Solomon Grundy, (really, a body possesed by the Swamp Thing) who has raised in Slaughter Swamp. Confident in his power will protect him, Laurence went to stop Grundy, but he fond himself overpowered by the elementally driven Grundy. Using his staff to discover the secret of the swamp, Black Box freed all the spirits trapped in the swamp, the soul of people killed and bodies buried in the dark waters. One of those bodies was the corpse of his son Michael. He discovered then it was his wife who killed his son, because she couldn't endure more the situation. She had to live with the kid alll the time meanwhile his father was far from home, in superheroic adventures. So she lied about the kidnapping and never said anything about that but she was all her life regreting her actions. The Black Box in a last effort send all the spirits to the other life and let the Swamp Thing continue his traveling.
For him however, he discoverd than not even magic could protect him from the secrets hide in his own home.
His powers, which are otherwise identical to golden age Green Lantern's (with a touch of Starman and Doctor Fate), but with a purple plasma instead green, do not effect organic matter (as opposed to merely wood).