[6] Kearney made modern Irish history his major research interest, especially focusing on Ireland's relationship with the United Kingdom, and the British nations.
[6] While at Sussex, Kearney spent three months at the Folger Library in Washington D.C., where he wrote an article Puritanism, Capitalism and the Scientific Revolution (published in Past and Present, 1964).
[2][6] While at Sussex, Kearney edited Problems and Perspectives in History (a series published by Longmans) in which he contributed the volume Origins of the Scientific Revolution.
[8] It was printed by Cambridge University Press as a general reader book with plate sections in hardback and paperback, and the Canto edition of 1995, which had an extended bibliography, was reprinted twice.
In 2006, Kearney reminisced with his daughter about life during the early development of Sussex University, in a BBC Radio 4 series charting the post-war history of higher education.