Sarah Simpson was a 27-year-old widow residing in Portsmouth, Province of New Hampshire. Details about her early life are scarce, but records indicate she had previously lived as an indentured servant, suggesting a life of hardship and limited means. As a widow, she likely faced significant social and economic challenges in colonial New England. In August 1739, following the discovery of a deceased infant girl in a well, suspicion fell upon Sarah due to her recent pregnancy. When questioned, she denied giving birth to a girl and instead led authorities to a shallow grave near the Piscataqua River, where the body of her infant son was found. She claimed the child was stillborn. Despite her assertion, she was arrested and charged under a 1714 New Hampshire law that made the concealment of a bastard child's death a capital offense, unless the mother could prove the child was stillborn.

In August 1739, the discovery of a deceased infant girl in a well near Portsmouth led to an investigation that uncovered Sarah Simpson's recent pregnancy. Upon questioning, she denied any involvement with the infant girl but admitted to the death of her own infant son, whose body she led authorities to near the Piscataqua River. She maintained that the child was stillborn. However, under the 1714 statute, her inability to provide a witness to confirm the stillbirth led to her being charged with "feloniously concealing the death of an infant bastard child," a capital offense at the time. ​

Sarah Simpson was tried and convicted in September 1739. On December 27, 1739, she was executed by hanging in Portsmouth, alongside Penelope Kenny, who had been convicted of a similar crime. Their executions were the first in New Hampshire's history and were carried out publicly before a large crowd. The event sparked ongoing debates about capital punishment in the colony.