Pan-Africanism is a cultural and intellectual movement which argues that Africans and people of African descent share certain interests and should therefore be united in some way. There are many different schools of thought within the movement, the most political of which advocate the establishment of a unified African nation. Cultural Pan-Africanism, on the other hand, emphasizes and celebrates the similarities that modern-day Africans and those of the African diaspora—such as African-Americans, for example—share.
W.E.B. Du Bois was a prominent exponent of a cultural Pan-Africanism that would involve, among other things, the intensive study of African history and culture by African-Americans. Like many black intellectuals, Du Bois believed that his fellow African-Americans were in danger of losing touch with their racial and cultural heritage. He believed that to stave this eventuality off, the diaspora community needed to reestablish a connection with the land of their ancestors.
A key part of establishing such a connection would be the recognition that the situation of African-Americans and those of native Africans shared a number of similarities. Du Bois saw the repression and subjugation of African-Americans and the colonial exploitation of Africans by European powers as all of a piece. These were not separate phenomena; they were both part of the same global problem: the problem of the "color line", the relation of what Du Bois called the "darker" to the "lighter" races.