(1821–1904), writer born in Plymouth, Massachusetts. Diaz grew up in an atmosphere of reform and was greatly influenced by her father, a leader in temperance and antislavery work. As an adult, she became involved in reform as the director of the Women's Educational and Industrial Union of Boston, and as vice president of the Massachusetts Woman Suffrage Association. However, after a failed marriage and many career changes, she was left to support her several small children alone. Her love for children led her to pursue writing as a career. Her work was published in numerous periodicals, such as St. Nicholas and Our Young Folks. Although she did write books for adults, she was best known for her children's books, especially The William Henry collection; of these, perhaps the most successful was The William Henry Letters, published in 1870.
From The Oxford Encyclopedia of Children's Literature in Oxford Reference.