Final answer:
Phillis Wheatley published her book of poems in England because her work was not embraced by publishers in the American colonies. Her success in London not only provided her with recognition but also contributed to her achieving freedom upon her return to Boston.
Step-by-step explanation:
Phillis Wheatley, an African-born poet who became a famous writer in 18th-century America, published her book of poems in England due to significant challenges in the American colonies. A proposed Boston publication of her book was unsuccessful; publishers in the colonies were not interested in a slave's writing. Instead, Wheatley and her mistress took the initiative to prepare her work for a London audience. In London, Wheatley's manuscript was not only accepted, but she also had a chance to promote her Poems and exert some control over the publication process. Wheatley's work ultimately found its way into print in 1773, winning her recognition in England and America, and even playing a role in securing her freedom after her return to Boston.