Marguerite Henry was born in Milwaukee, Wisconsin, the youngest of the five children. At age 6 she became sick with rheumatic fever and remained bedridden for six years, unable to attend school. She spent her days reading and writing. Her first story was published when she was 11 years old. After highschool she attended Milwaukee State Teachers College. In 1923, she married. She and her husband lived in Wayne, Illinois.
In 1945, Henry received the Newbery honor for Justin Morgan Had a Horse. She began collaborating with artist Wesley Dennis, who went on to illustrate 15 of her books. In 1947, she published her most famous book, Misty of Chincoteague. In 1949 she received the Newbery Medal in 1949 for King of the Wind. Over the course of her career, she published over 40 books, chiefly fiction about horses.
