How far did NSW extend?

Answer 1

The border of New South Wales was moved several times.
When James Cook first claimed the eastern coast of the Australian continent for England and named it New South Wales, it extended from latitude 38 degrees S to latitude 10.5 degrees S, from the tip of Cape York to where he first sighted the continent, in what is now far eastern Victoria.

When Captain Arthur Phillip led the First Fleet, according to his journals, he was required to extend the boundary of NSW “... extending from the Northern Cape or extremity of the coast called Cape York, in the latitude of ten degrees thirty-seven minutes south, to the southern extremity of the said territory of New South Wales or South Cape, in the latitude of forty-three degrees thirty-nine minutes south and of all the country inland westward as far as the one hundred and thirty-fifth degree of east longitude reckoning from the meridian of Greenwich, including all the islands adjacent in the Pacific Ocean within the latitudes aforesaid of ten degrees thirty-seven minutes south and forty-three degrees thirty-nine minutes south”. He also included Van Diemen's Land (now Tasmania) within the boundary of New South Wales. At this time, Van Diemen's Land was not known to be an island.

In 1825, Governor Ralph Darling extended the western boundary of New South Wales to 129 degrees E.