Author. Born Marguerite Breithaupt in Milwaukee, Wisconsin, the youngest of seven children of Anna Kaurup and Louis Breithaupt. Her father owned a publishing house and his daughter developed an interest in books and writing. She sold her first magazine article at the age of eleven. She attended the Milwaukee State Teachers College and the University of Wisconsin in Milwaukee. On May 5, 1923, she married Sidney Crocker Henry. She sold a handful of articles to the Saturday Evening Post and wrote several information books for children. Her first full-length story book, published in 1940, was entitled "Auno and Tauno: A Story of Finland." Several other unremarkable children's books followed, including "Dilly Dally Sally" in 1940 and "Geraldine Belinda" in 1942. "Justin Morgan Had a Horse", the history of the Morgan horse, published in 1945, was the first of her children's novels to win critical acclaim. It also marked the beginning of a long partnership with illustrator Wesley Dennis. In 1947, her most enduring story, "Misty of Chincoteague," which was also based on actual events, was named a Newbery Honor Book and won the Lewis Carroll Shelf Award. A motion picture based on the novel was produced in 1961. Several sequels were eventually written including "Sea Star: Orphan of Chincoteague" (1949), "Stormy, Misty's Foal" (1963), and "Misty's Twilight" (1992). Other equine-starred stories became staples, including "King of the Wind" (1948), winner of the Newbery Medal and the Young Readers Choice Award; "Born to Trot" (1950), "Black Gold" (1957), "White Stallion of Lipizza" (1964), "Mustang: Wild Spirit of the West" (1966), and in 1953 she published "Brighty of the Grand Canyon," winner of the William Allen White Award. It was adapted as a 1967 feature film. In 1990, the Misty of Chincoteague Foundation, a nonprofit organization dedicated to preserving the wild Assateague ponies was formed with Henry's assistance. She completed her last book, "Brown Sunshine of Sawdust Valley" in 1996. She died at home in Rancho Sante Fe, California, the following year at the age of 95. At the time of her death, she had published more than 60 books for children.