"Was it a specific grower? How did it become so popular here?"
Interesting question requiring some research :)
Cannabis has been documented as living alongside humans from at least as far back as 2900 B.C. It is thought to have originated from Afghanistan and Pakistan, spreading to Asia and Russia to the northeast and Africa, South America, and Africa to the southwest.
Regional strains adapted to their environment, giving them unique properties, and were cultivated for medicinal and religious purposes by local peoples. These pure/un-hybridized strains are referred to as landraces. Durban poison is thought to be one such unadulterated sativa strain originating from the Durban port city of South Africa.
It is said that the legendary cultivator Ed Rosenthal was searching for new genetics in South Africa in the early '70s, where he procured these Durban seeds. The strain has gained popularity worldwide for having highly energizing and uplifting effects.
From a medical standpoint, Durban poison may be helpful in providing mental focus for patients with ADHD and in the treatment of depression and fatigue.