Harriett Mulford Stone was born in New Haven, Connecticut. In 1878, at the age of 34, she began sending short stories to Wide Awake, a children's magazine in Boston. Two of her stories, "Polly Pepper's Chicken Pie" and "Phronsie Pepper's New Shoes", proved to be very popular with readers. Daniel Lothrop, the editor of the magazine, requested that Stone write more. She wrote the now-famous Five Little Peppers series. This series was first published in 1881, the year that Stone married Daniel Lothrop. Daniel had founded the D. Lothrop Company of Boston, which published Harriett's books under her pseudonym, Margaret Sidney. Her husband died in 1892, and Harriett suspended her writing for five years while she continued to run the publishing company. Eventually, she sold the company and resumed writing the Five Little Peppers series. Over the course of her career, she wrote over 30 books. In addition to the Five Little Peppers series, she wrote several books on patriotic themes, including A Little Maid of Concord Town and A Little Maid of Boston.