John William Downer was born in Adelaide in 1843 into a colonial society still finding its footing in law and governance. He attended St Peter’s College and then studied law at the University of Adelaide. He was admitted to the South Australian Bar in the 1860s and quickly developed a reputation as a commanding courtroom advocate with a penetrating intellect and a measured style. Downer’s legal practice spanned a wide range of subjects, but he was most respected for his skill in constitutional law and civil litigation.

He approached legal argument with both structure and flair, and his ability to dissect statutory meaning made him one of the leading barristers in the colony. Downer’s reputation was built not only on eloquence but on a consistency of thought that judges found persuasive and opponents respected. He appeared regularly before the Supreme Court of South Australia and was often instructed in matters involving constitutional principles and the limits of executive power.

Downer entered politics at a young age and was first elected to the South Australian House of Assembly in the early 1870s. Though he never formally retired from legal practice, politics became the arena in which he applied his legal training to lasting effect. He served twice as Premier of South Australia and was a consistent advocate for responsible government and the development of strong legal institutions.

One of his enduring contributions came during the movement for Australian Federation. Downer was an influential figure at the Federal Conventions and worked closely with other colonial leaders to draft and refine the Constitution. His concern was always to preserve the rights of the smaller states and to ensure that the new Commonwealth would not trample state sovereignty.

Appointed to the South Australian Legislative Council in his later years, Downer continued to influence policy with legal insight and measured judgment. He was knighted for his service to the colony and the nation. He died in 1915, having left a legacy of principled advocacy and statesmanship. His work at the Bar and in the service of the law stands as an example of how legal knowledge can shape both courtroom outcomes and the destiny of a nation.