[2] Merrill was the founder and first principal of the Willard Hall School for Girls.
She taught next at Lyons Female College, Clinton, Iowa before returning to Boston as first assistant in the Burroughs Street Boys' Grammar School, leaving that to go to the Perkins School for the Blind at South Boston.
Following these experiences, she was for seven years, in charge of the scientific department in Bradford academy.
In 1893, after being widowed, Merrill removed the school to larger buildings, which she remodelled, enlarged, and renamed Willard Hall.
[2] Sarah M. Dawson Merrill died in Danvers, Massachusetts on August 17, 1899.