I think England was earlier than the U.S., although they might have been influenced by our abolitionists, who screamed for a long time before the Civil War. The England that our president loves to hate.
You are right. “. . . Slavery was abolished throughout the British Empire by the Slavery Abolition Act 1833, with exceptions provided for the East India Company, Ceylon, and Saint Helena. These exceptions were eliminated in 1843.[2]”
The above quoted FRom a Wikipedia article on the subject at https://en.wikipedia.org/wiki/Slavery_in_the_British_Isles.