

The Sign of the Beaver (1984) was a Newbery Honor winner, and won the Scott O'Dell Award for Historical Fiction and the Christopher Award. She earned her second Newbery Medal for her third book, The Bronze Bow, published in 1961. Ideas and inspiration for both books came to Speare while she was researching the history of New England and Connecticut, respectively. The next year she completed her second historical novel, The Witch of Blackbird Pond, which won numerous awards including the Newbery Medal. It features a colonial New Hampshire family kidnapped by Native Americans in 1754. Speare's first book, Calico Captive, was published by Houghton Mifflin in 1957. Eventually her work saw circulation in Better Homes and Gardens, Woman's Day, Parents, and American Heritage. She also wrote many other magazine articles based on her experiences as a mother, and even experimented with one-act plays. Speare's first published work was a magazine article about skiing with her children. Speare began to focus seriously on literature when her children were in junior high school.

Although Speare always intended to write, the challenges and responsibilities of being a mother and wife drained her of any free time. In 1936, she met her future husband, Alden Speare, and together the two moved to Connecticut where they married and raised two children Alden, Jr., who was born in 1939, and Mary in 1942. After completing her Bachelor of Arts degree at Smith College in 1930, she earned her Master's degree in English from Boston University and taught English at several private Massachusetts high schools from 1932 to 1936.

Speare discovered her gift for writing at the age of eight and began composing stories while still in high school. Speare lived much of her life in New England, the setting for many of her books.

She had an extended family with one brother and many aunts, uncles, and cousins, and most importantly, very loving and supportive parents. Her childhood, as she later recalled, was "exceptionally happy" and Melrose was "an ideal place in which to have grown up, close to fields and woods where we hiked and picnicked, and near to Boston where we frequently had family treats of theaters and concerts." Speare was born in Melrose, Massachusetts to Harry Allan and Demetria (Simmons) George.
