One of the earliest and most systematic studies of urban concentrations in Nigeria was made by Mabogunje (1968) who found that historically, there have been two main types of such concentrations. First, there were pre-industrial and pre-colonial urban settlements which grew as centers of import and export trade and commerce involving gold, salt, pepper, minerals, craft products, textiles, gunpowder, slaves, coral beads, ivory, horses, and manufactured goods. Second, colonial and postcolonial industrialized centers offered urban context for population concentration. In a broad sense, these two categories correspond to the African Type A and Type B town formations presented by Southall (1961: 6-13).
By their 1917 Township Ordinance in Nigeria, the British Colonial Government established first, second and third class categories of townships on the basis of which population, utilities and services, including water supply, roads, and electricity, were provided. Such basic infrastructures produced changes in the economic foundations of the township and facilitated the work of increasing numbers of administrators and professionals. Apart from rearranging the economic, political, and administrative spatial integration of these townships, the new developments increased the use of urban technologies thereby attracting further population growth.
The two categories of urban population concentrations referred to above may merely be regarded as dated analytical distinctions because in the contemporary Nigerian situation, the pre-colonial, pre-industrial features in any one town vary in content in comparison with the post-colonial industrial characteristics; both co-exist and the latter may be regarded as extensions and revivals of the former. On the basis of this insight, it is obvious that there are several sources of urban population concentrations in Nigeria, each center having its own peculiar cluster of spatial, socio-economic, and socio-political characteristics.