The Answer:

Sure. The poem was originally called "Mary's Lamb" and it was written by Sarah Josepha Hale. It first appeared in a book of verses called "Poems For Our Children" in 1830.

After the poem was published, a woman named Mary Sawyer, who as a young girl went to school at Redstone School in Sterling, Mass., claimed she was the "Mary" in the poem. In 1817 she did have a lamb follow her to school and she remembered being handed a poem about the event by 12-year-old John Rhoulstone. There is no evidence of whether or not Hale ever saw that poem.

—The Fact Monster