[5] Returning to Canada in 1939, Ferns joined the civil service and worked for a time in the private office of the Canadian Prime Minister, Mackenzie King, before leaving in 1944 to teach at his alma mater, the University of Manitoba.
[5] Having been offered and then denied the opportunity to lecture in history at a naval college in British Columbia – which he believed was due to his having been blacklisted – he later returned to Cambridge to study for a PhD.
[1] In 1950 he obtained a post teaching modern history and government at the University of Birmingham, becoming professor and founding head of the political science department in 1961.
In 1960, he published Britain and Argentina in the Nineteenth Century, which "established his eminence as a scholar in Latin American affairs".
[9] His efforts in this area were eventually rewarded with the establishment in 1976 of the University of Buckingham, Britain's first modern-day private higher education institution.