Who is Ellen Tucker from Selected Writings of Ralph Waldo Emerson and what is their importance?

Ellen Tucker was Emerson's first wife, who died two years after their marriage of tuberculosis in 1829. She is immortalized in Lines to Ellen, Emerson conflates his belief in transcendentalism with his grief over his departed wife: "Tell me, maiden, dost thou use/Thyself thro nature to diffuse?/All the angles of the coast/Were tenanted by thy sweet ghost/Bore thy colors every flower/Thine each leaf and berry bore."