As a girl, Mary Sawyer (later Mrs. Mary Tyler) kept a pet lamb, which she took to school one day at the suggestion of her brother. A commotion naturally ensued. Mary recalled, “Visiting school that morning was a young man by the name of John Roulstone, a nephew of the Reverend Lemuel Capen, who was then settled in Sterling. It was the custom then for students to prepare for college with ministers, and for this purpose Mr. Roulstone was studying with his uncle. The young man was very much pleased with the incident of the lamb; and the next day he rode across the fields on horseback to the little old schoolhouse and handed me a slip of paper which had written upon it the three original stanzas of the poem. . . .” (The Story of Mary’s Little Lamb, Dearborn, 1928, p. 8).
There are two competing theories on the origin of this beloved poem. One holds that Roulstone wrote the first twelve lines and that the final twelve lines, more moralistic and much less childlike than the first, were composed by Sarah Hale; the other is that Hale was responsible for the entire poem.