"To the Right Honourable William, Earl of Dartmouth" by Phillis Wheatley (1753 - 1784) was offered by Poets.org's Poem-A-Day on September 15, 2013. Miss Wheatley, a slave who was allowed an education by her master, Boston merchant John Wheatley, was the first person of African descent to publish a collection of poetry in North America and also the third woman to do so. The Second Earl of Dartmouth (pictured) was the Secretary of State for the American Colonies from 1772 - 1775 and a prominent abolitionist and philanthropist.
The poem was published in 1773 as a part of a collection entitled, Poems on Various Subjects. Its heroic couplets are at once a diatribe against slavery and a tribute to a leader who would see it abolished. For more information, see the following website: http://www.poetryfoundation.org/bio/phillis-wheatley.