Mary Lou Curtis joined the Manhattan Project in Dayton, Ohio in 1943.
Mrs. Curtis worked in the Counting Room at Monsanto's Unit III facility, where she developed new methods to measure and analyze radioactive materials, such as polonium, which was used as the trigger for the atomic bombs. She was one of the few women scientists who worked at Dayton, and she encountered difficulties throughout her career as a result.
After the War, Curtis continued to work at Monsanto and relocated to Mound Laboratory in 1950, where she would work for the next twenty-four years. Mrs. Curtis became one of the leading experts in her field and eventually published over twenty papers on radioactive counting methods in several different scientific journals.