Together with Olaudah Equiano and other educated Africans living in Britain, Cugoano became active in the Sons of Africa, an abolitionist group whose members wrote frequently to the newspapers of the day, condemning the practice of slavery.

[8] In 1787, possibly with the help of his friend Olaudah Equiano, Cugoano published an aboitionist work entitled Thoughts and Sentiments on the Evil and Wicked Traffic of the Slavery and Commerce of the Human Species (1787).

[9] A shorter version of the work was published in 1791, with subscribers including prominent artists such as Cosway, Joshua Reynolds, James Northcote and Joseph Nollekens, "indicating their support of Cugoano's mission".

[10] In the shortened work, addressed to the "Sons of Africa", Cugoano expressed qualified support for the efforts to establish a colony in Sierra Leone for London's "Poor Blacks" (mostly freed African-American slaves who had been relocated to London after the American Revolutionary War; other early settlers were the Nova Scotian Settlers, that is Black Loyalists, also former American slaves, from Nova Scotia, who chose to move to Sierra Leone).

Cugoano wished to travel to Nova Scotia to recruit settlers for the proposed free colony of African Britons in Sierra Leone but it is not known if he did so.

[11] In November 2020, an English Heritage blue plaque honouring Cugoano was unveiled on Schomberg House in Pall Mall, London, where he had lived and worked with the Cosways from 1784 to 1791.