Blackwell applied to numerous medical schools throughout the northeast. Her acceptance by Geneva Medical College in New York (today Hobart and William Smith Colleges) was sort of an accident. The school allowed the all-male student body to vote whether to accept Elizabeth. To make a joke of it, they voted yes. As a result, she was accepted in 1847 and graduated two years later. She then traveled to Paris to further her studies in obstetrics but returned to New York City after losing sight in one eye and therefore the opportunity to study surgery.
After turned down from a job in a women's department at another dispensary, Blackwell decided to open her own in 1853 in New York City. This dispensary grew quickly and became the Infirmary for Women and Children in 1857. By 1967, the Infirmary opened a medical school for women. She later established a similar school in London. Along with her sisters, Blackwell partook in the aiding soldiers in the Civil War. When the United States Sanitary Commission rejected her plan to train nurses, Blackwell and her female colleagues established the Women's Central Association of Relief. The Association worked with the Army to select, train, and communicate with nurses across the Union, while also coordinating the collection and dissemination of supplies. Blackwell personally met with the Army Medical Department and the Secretary of War to advocate for her cause.
Though health issues forced her to retire from medicine in 1877, Blackwell remained an active figure in the medical field. She returned to Europe and was involved in social and health reform campaigns, and was especially interested in the intersection of medicine, morality, and religion. She published nearly twenty books in her lifetime. She died in 1910 in England. In 2003, the Ohio Bicentennial Commission and Ohio Historical Society (today the Ohio History Connection) recognized her contributions to medicine and her residence in Cincinnati with a historical plaque at the YWCA.