Marie enrolled in the doctoral program at Columbia University after working for a year tutoring chemistry students at Queens College.
She was awarded her doctoral degree in 1947, only three years after enrolling in the program.
She was the first African American woman to obtain a Ph.D. in chemistry in the United States.
After completing her doctoral degree, Daly taught for two years at Howard University in Washington, D.C.
Then Daly took a new position teaching biochemistry at the College of Physicians and Surgeons of Columbia University.
In 1960 she became a professor at the Albert Einstein College of Medicine, where she remained until her retirement in 1986.
