 Born, raised and educated in South Africa, of Irish descent, Coghlan moved to Bulawayo in 1900 to practise as a lawyer.He was elected to the Southern Rhodesian Legislative Council in 1908, representing the Western electoral district.Over the next decade he supported the renewal of the British South Africa Company's royal charter to administer the Rhodesias, and opposed Southern Rhodesia's amalgamation with either Northern Rhodesia or the Union of South Africa.