Hugh Clapperton's Journal of a Second Expedition into the Interior of Africa (1829) is the posthumously published account of the Scottish explorer's mission to the Sokoto Caliphate, in the central part of the region then known as the Sudan. The volume presents a slightly abridged version of the diaries and notebooks to which the editor, John Barrow, had had access, leaving out the pages recording the voyage and the initial stages of the journey, from the Coast of Sierra Leone to Badagry. The journal thus covers the period from December 1825, when Clapperton, then a Royal Navy commander, arrived in Badagry, in the Bight of Benin, to March 1827, when he arrived in Sokoto, where he was to die of dysentery a month later. The entire region is now part of Nigeria. This ‘second’ expedition was the immediate continuation of one undertaken from 1822 to 1825, in which Clapperton, together with two companions, Dixon Denham and Walter Oudney, had travelled across the Sahara, from Tripoli to Borno and Sokoto; it shared, then, the destination of that earlier expedition, but differed in its use of a different, southern route that started on the Guinea coast.

Published in logbook form, without the subsequent elaboration of a narrative, the text offers no kind of explanation as to the objectives of the mission, contenting itself with recording the explorer's progress from the coast through Yorubaland, Borgu, Nupe and Hausaland to Sokoto, and his contacts with the populations of these small kingdoms. Some of these objectives may nonetheless be inferred from a variety of elements in the journal, in particular the subjects of Clapperton's observations, which are frequently geographical and economic, and the presence of reported conversations in which summary explanations of the mission's objectives are offered to the explorer's African interlocutors. Clapperton's concerns seem to have been the charting of previously unknown regions – in particular, he was seeking to gain knowledge of the course of the Niger – as well as the promotion of the development of Anglo – African commerce.