Quobna Ottobah Cugoano, also known as John Stuart (c. 1757 – after 1791), was an African abolitionist and natural rights philosopher from Ghana who was active in England in the latter half of the eighteenth century. Captured in present-day Ghana and sold into slavery at the age of 13, he was shipped to Grenada in the Lesser Antilles, where he worked on a plantation. In 1772 he was purchased by an English merchant who took him to England, where he was taught to read and write, and was freed following the ruling in the Somersett Case (1772). Later working for artists Richard and Maria Cosway, he became acquainted with British political and cultural figures. He joined the Sons of Africa, African abolitionists in England.