Sarah O. Bagley (1824-1905), a resident of Amesbury, Massachusetts, was one of Mary Baker Eddy's first students, and the two had a warm personal friendship for several years. Eddy lived briefly with Bagley in 1868 and 1870; it was during this second stay that Eddy taught Bagley her method of metaphysical healing. Years earlier, at age 16, Bagley was awarded her teacher's certificate by John Greenleaf Whittier, a member of the Amesbury school committee. She went on to teach in the Massachusetts towns of Amesbury, Georgetown, and Methuen. Although instructed by Eddy, Bagley later diverged from Christian Science. For many years she practiced successfully as a mental cure doctor in and around Amesbury, honoring her agreement with Eddy to pay her a percentage of her practice for 5 years.