He served on various university boards and committees and was once secretary of the Ghana National Committee of the Encyclopedia Africana Project. He was the external examiner for history for universities in Ghana and the West African sub region. Some of these universities they include; the University of Cape Coast (1987 to 1990), the Kwame Nkrumah University of Science and Technology (1990 to 1992), Fourah Bay College (1984 to 1986). He also served as an external examiner for the West African Examinations Council from 1965 to 1969. He retired as a lecturer of the University of Ghana in 1995 however he continued teaching history at the university on contract basis. In 1985 he was enstooled nifahene of the Abura traditional area of the Central Region of Ghana with the stool name; Nana Budukuma IV. John authored articles in many journals and also served on boards of countless journals. On the week when he defended his doctoral dissertation entitled: "Asante and Its Neighbours, Circa 1700–1807", he was approached by Longman publishing company who wanted to publish the manuscript with the same title. His first publication however was "Asante and Its Neighbours, Circa 1700–1807" published by Longman in 1964. His other publications include:  John was a recipient of local and international honours. In 1970, he was made honorary citizen of Sioux City, Iowa. In 1982 he won the Ghana Book Development award. He was awarded a Senior Fulbright Research Award at the University of Wisconsin from 1992 to 1993. He was married to Mrs. Theodora Fynn ("née" Amorin). Together they had seven children. He died on 25 August 2005.