Adelaide was founded in late 1836 and with vines planted in 1837 the region was for a few decades a producer of wine. As the city expanded the vines retreated. Tha happened as well in the capitals Sydney and Melbourne.
Early plantings were on the flat plains. More interesting vineyards were planted on the hilly slopes that overlooked Adelaide. Auldana and the Penfolds property of Magill are famous examples.
There were still enough bearing vines in the early 1950s for Max Schubert to use almost 100% Adelaide fruit for his famous experiments to make classical warm climate reds in. The vineyards on the plains were gone though he found enough along the slopes and gullies to the east of the town.
Magill has been preserved and a small Grenache vineyard still exists on the flats at Marion though releases 15 years ago were regrettably treated with no respect.
See HERE for details of other South Australian wine regions