Short answers, pulled from the story.
Dave Arneson created the Blackmoor campaign setting in 1971. The Blackmoor supplement was not published until 1975, and Arneson and Zeitgeist Games officially republished the setting in 2004.
The Dark Sun campaign setting released by TSR in 1991 is set on the harsh desert world of Athas. This world was once lush before uncontrolled defiling magic stripped it of its fertility, leaving a desolate place controlled by god-like Sorcerer-Kings.
The Ghostwalk setting consists of a single campaign book centered on the city of Manifest. This city is a mausoleum built atop a geological feature known as the Well of Souls, serving as a gathering place for ghosts to cross over to the realm of the living.
Tracy and Laura Hickman created the Ravenloft gothic horror setting, which was released as Module I6: Ravenloft in 1983 by TSR. The setting was further expanded into a campaign setting for the AD&D 2nd edition beginning in 1990 with the Realm of Terror boxed set.
The Eberron campaign setting was released in 2004 after winning a contest held by Wizards of the Coast in 2003. This setting takes place in a world of pulp action and fantasy noir with steampunk influences where inhabitants make extensive use of magic in place of technology.
The Malatra campaign setting started during second edition in 1995 and continued to release adventures through 2003. This setting is a massive plateau located south of Shou Lung in Kara-Tur that is loosely based on pre-colonial Indochina.