Garran became involved with the work of Edmund Barton, who would later be the first Prime Minister of Australia but at the time was the de facto leader of the federation movement in New South Wales as Sir Henry Parkes declined into poor health. Garran, along with others such as Atlee Hunt, worked essentially as secretaries to Barton's federation campaign, drafting correspondence and planning meetings. At one late night meeting, planning a speech Barton was to give in the Sydney suburb of Ashfield, Barton coined the phrase "For the first time, we have a nation for a continent, and a continent for a nation"; Garran recalled that the now famous phrase "would have been unrecorded if I had not happened to jot it down."[8]