Elizabeth Stuart (Phelps) Ward was born Mary Gray Phelps in Boston, Massachusetts, on August 31, 1844, the daughter of Elizabeth (Stuart) and Austin Phelps. In 1848, her father became professor of sacred rhetoric and homiletics at the Andover (Mass.) Seminary; her mother was a writer specializing in religious tales. Mrs. Phelps died when Mary was eight years old; after her death, Mary changed her name to Elizabeth Stuart Phelps as a tribute to her mother, and later used it as her official pen name. She attended Abbott Academy and Mrs. Edward's School for Young Ladies, both in Andover, but her education was also heavily influenced by her father.

The early death of her mother, the loss of a beloved boyfriend to the Civil War, and the atmosphere of a powerful religious education all combined to influence Elizabeth Phelps' writings. The Gates Ajar, published in 1868, a story conveying the happiness and peace of heaven, was her most popular success as it was greatly appreciated by thousands of families grieving their losses from the Civil War. For many years Elizabeth Phelps wrote articles on social reform for the Independent magazine, including pieces on women's rights and temperance; late in her life she took up the causes of antivivisection. She wrote poetry and fiction as well, and published 57 books during her writing career. She was the first woman to present a lecture series at Boston University. At the age of forty-four, Elizabeth Stuart Phelps married the son of her editor at the Independent, Herbert Dickinson Ward, who was seventeen years her junior. They had no children. Herbert Ward, also a writer, collaborated on several books with his wife. They were residents of Newton Center and East Gloucester, Massachusetts, where Elizabeth Phelps had summered for many years. Elizabeth Stuart Phelps Ward suffered from poor health for many years and died in Newton Center on January 28, 1911.