According to Biography.com, an important early inspiration for Emily Dickinson was Leonard Humphrey, the principal of Amherst Academy, where she attended school. A biography at the Poetry Foundation points out that the classes she attended at Amherst gave her the richness of detail found in her poems, and that her poetry gave her a means to express herself despite the strictures imposed upon women in the 1800s.
Emily Dickinson began writing poetry while she was still a teenager at Amherst Academy. When she returned home after only one year at a seminary, she continued reading and writing poetry. Family friends often gifted her with new volumes by poets such as William Wordsworth, Ralph Waldo Emerson and Henry Wadsworth Longfellow. Tragedies such as the death of Leonard Humphrey and the chronic illness of her mother exacerbated her isolation. She became more and more withdrawn until she rarely left the house or even her room.
According to the article on the Poetry Foundation website, poetry was her means of escape from her self-imposed exile from society. It helped her assert independence and rebel from the conservative stereotypes of the era. However, though she wrote more than 1,800 poems, fewer than 10 were published during her lifetime. Most of them were discovered by her family, in 40 hand-bound volumes, after her death. The first volume of her poetry, published four years after she died, was a commercial and critical success. Since then, she has been acknowledged as one of the greatest American poets.