In 1897, Garran published The Coming Commonwealth,[11] an influential book on the history of the Federation movement and the debate over the 1891 draft of the Constitution of Australia. The book was based on material he prepared for a course on federalism and federal systems of government, which he had planned to give at the University of Sydney, but which failed to attract a sufficient number of students.[1] Nevertheless, the book was both unique and popular, as one of the few books on the topic at the time, with the first edition quickly selling out. Soon after its publication the Premier of New South Wales George Reid, who had been elected as a New South Wales delegate to the 1897–1898 Constitutional Convention, invited Garran to be his secretary.