Mary was the daughter of Primus Easton of Hatfield, Massachusetts. According to federal census reports, she was one of four in the "All Other Free Persons" column in 1800 and in 1810, she was one of five. In the 1820 census she appears in the column for females aged 14-26 years. Mary doesn't appear in census reports again until 1850, in nearby Northampton. She is listed as being "Black", age 53, and living with her husband, Peter Salisbury. In the 1860 census Mary is "Colored", age 64, and living with Leonard Remington, age 33, and Mary Remington, age 10. They might be relatives.
Mary Easton Salisbury died on September 25, 1867, in Northampton, Massachusetts. She was 71 years old.