Between the British establishing settlements in Australia and before to 1901, Australia was divided into six colonies, each with its own constitution and laws governing transportation, commerce, postal services, immigration, and defence. This made it difficult to enforce laws throughout the six nations, trade and transportation were costly and sluggish, and individual states lacked a solid defensive system. Because of these issues, there was a growing desire for the individual colonies to merge into one nation. Australia had already formed a strong national identity, national sports teams, and a distinct Australian culture by the second part of the nineteenth century. There were difficulties along the road, but the colonies formed a federation on January 1, 1901.
The Commonwealth of Australia was created by the Commonwealth of Australia Constitution Act 1900, which was approved in the British parliament and established Australia’s state as an independent nation.
The Australian Parliament, comprised of the House of Representatives and the Senate, was established by the Constitution. It also established the High Court of Australia, which is the last arbitrator of how Australian laws are enforced and interpreted.
The people of Australia can modify the Australian Constitution by voting in a referendum; for example, a 90% majority agreed in 1967 that Aboriginal peoples should be counted in the national census. If a referendum is held, the outcome must have a “double majority” in order to modify the constitution.