Eleanore M. Jewett was born in New York City in 1890. She found it to be a somewhat lonely city for an only child, but the fact that one side of her family had been there since it was a small Dutch village made her feel like she "practically owned the place." Her solitude caused her to create imaginary friends with whom, at around the age of nine, she even formed a literary club. Since young Eleanore was the only one who actually could put pen to paper the club died a natural and early death, but she dates her ambition to write for children from this time.
When Mrs. Jewett was doing a Master's degree in comparative literature at Columbia University she became deeply interested in the medieval period, a fascination begun many years earlier after hearing a story about King Arthur. The Hidden Treasure of Glaston, a story of mystery set at Glastonbury Abbey around 1171 in the days of King Henry II of England, and Big John's Secret,were direct and satisfying results of this interest. The Hidden Treasure received a Newbery Honor in 1947.
The truth and nobility which she infused into her historical novels was also something valued in her daily life. Big John's Secret, whose hero comes to have a deep interest in the art of healing, took inspiration from Mrs. Jewett's experience as wife of a committed physician. In her dedication to the book she bears witness to this.
After their marriage, the Jewetts moved from New York City to a town in upstate New York where they lived with their two daughters. Eleanore Jewett died in 1967, leaving a small but solid contribution to the field of children's literature.