As well as Cowan, the $50 banknote features Indigenous preacher, writer and inventor David Unaipon. Tiny snippets from his book Legendary Tales of the Australian Aborigines, are included on the note.

In May 1990, when the Reserve Bank of Australia (RBA) announced plans to replace Caroline Chisholm with the Queen on a new $5 note, the decision stoked growing republican sentiment and unleashed a ...