Shepperson was a pathbreaking historian of the African Diaspora, the history of the African peoples and their spread across the world and was awarded the 'Distinguished Africanist' award in 2007 from the African Studies Association of the United Kingdom. His research specialism was Malawian history, but he also wrote on African-American history (and was chair of the British Association for American Studies from 1971-74) and black British history (particularly relating to the black presence in Scotland. Many of his writings, including on John Chilembwe and the Chilembwe uprising, are seen as seminal contributions. "Independent African: John Chilembwe and the Origins, Setting and Significance of the Nyasaland Native Rising 1915" (1958) was one of the first scholarly works on African history and was widely read by African nationalists after its publication. Shepperson provided an account of his life as an Africanist historian as a contribution to "The Emergence of African History at British Universities: An Autobiographical Approach" (1995, edited by Anthony Kirk-Greene).