The exact date and location of Mary Elizabeth Walton's birth are currently unconfirmed. However, based on the timing of her patents and societal norms of the era, it is believed she was born sometime in the 1820s or 1830s. Information about her early life, education, and upbringing is limited, though like most women of the era she likely was not given the same educational opportunities as men, thus her inventiveness is particularly noteworthy.

Walton received her first patent for a device designed to deflect smoke emitted by locomotives. This device utilized a system of water tanks and diversion structures to filter and redirect the smoke, mitigating the nuisance and health hazards it posed to urban dwellers living near railway lines. Her invention showcased an early understanding of air pollution's negative impacts and offered a practical solution.