[1] He joined The Times in 1894 and reported on major events such as Queen Victoria's Diamond Jubilee and the Boer War.

[1] As well as his work for The Times, MacDonagh contributed articles to magazines on his favourite subjects of Irish history and literature, and parliamentary procedures and traditions.

He authored biographies of James Warren Doyle, Daniel O'Connell and William O'Brien, and was a supporter of the Irish Home Rule movement.

Before the First World War the leader of the Irish Nationalist Party, John Redmond, had promised MacDonagh the office of Clerk of the Irish House of Commons but subsequent events prevented his appointment.

[1] MacDonagh was one of the first members of the Institute of Journalists and he was a founder of the Irish Literary Society, for which he later served as vice-president.