Which organization promoted the concept of Pan-Africanism?

In London, the Sons of Africa was a political group addressed by Quobna Ottobah Cugoano in the 1791 edition of his book Thoughts and Sentiments on the Evil of Slavery. The group addressed meetings and organised letter-writing campaigns, published campaigning material and visited parliament. They wrote to figures such as Granville Sharp, William Pitt and other members of the white abolition movement, as well as King George III and the Prince of Wales, the future George IV.

Modern Pan-Africanism began around the start of the 20th century. The African Association, later renamed the Pan-African Association, was established around 1897 by Henry Sylvester Williams, who organized the First Pan-African Conference in London in 1900.