Why did New South Wales join the Commonwealth of Australia in 1901?

New South Wales joined the Commonwealth of Australia in 1901 as part of a broader movement toward national federation, driven by several key political, social, and economic motivations:

• Defense and Security: Following the Crimean War, there was widespread concern regarding potential incursions from European or Asian powers. A unified national government was seen as essential for providing more effective defense.1
• Immigration Policy: There was a strong desire among the colonies to establish a coordinated approach to restricting Asian immigration, which became a central goal of the new Commonwealth.12
• Economic Interests: Establishing intercolonial free trade was a significant objective, as it promised to remove barriers to commerce between the colonies.1
• National Identity: By the 1890s, a growing sense of national feeling had emerged, fueled by a population that was increasingly Australian-born. This cultural shift, reflected in art and literature, provided momentum for the federation movement.3

While political leaders like Sir Henry Parkes were instrumental in advocating for the cause, the process involved over a decade of negotiation and constitutional referenda before New South Wales and the other colonies formally united.13