First work published in the usa by a black person in 1865 , circa after the thirteenth amendment, by the only person to publish poetry while enslaved in the history of the U.S.A. is attributed to George M Horton.  He published three works while planned four in total, to my knowledge through Wikipedia.   The Hope of Liberty (1829) This was Horton's first true attempt to buy his freedom. Most of the poems in the collection were themed around antislavery either indirect or directly