South Australia
The question does not make sense. All of the states of Australia share a border with another state. Even Tasmania, the island state, shares an actual land border as well as a water border with another state.
There is no Australian state which shares a border with all other states. No state except for Victoria shares a land border with Tasmania. South Australia shares a border with all mainland states and the Northern Territory.
The Great Australian Bight is bordered by the two states called South Australia and Western Australia.
Western Australia to the West, South Australia to the South and Queensland to the East.
South Australia
Border taxes were part of the Australian life before federation. Time of border states? the border states at the time of the civil war were de KY MD mo & wv the ... How have state borders of Australia changed from the early 1800s to the time of ...
No town in South Australia lies on the border with Victoria. The closest is probably Frances, a small township with a population of about 50, between Bordertown and Naracoorte on the now disused railway line. It is about 1 kilometre west of the border.
Tasmania has no border with South Australia.
South Australia borders the most states and territories in Australia. South Australia shares borders with Western Australia, the Northern Territory, Queensland, New South Wales and Victoria.
Federation was good for Australia. It led to a unified defence force; common laws across the states; and the abolition of border taxes.
Victoria is bordered by New South Wales to the north and South Australia to the west. It has both a sea border and a separate land border with Tasmania.