When Elizabeth Blackwell returned to the United States in 1859, she resumed work with the Infirmary. During the Civil War, the Blackwell sisters helped to organize the Women's Central Association of Relief, selecting and training nurses for service in the war. This venture helped to inspire the creation of the United States Sanitary Commission, and the Blackwells worked with this organization as well.
A few years after the end of the war, in November 1868, Elizabeth Blackwell carried out a plan that she'd developed in conjunction with Florence Nightingale in England: with her sister, Emily Blackwell, she opened the Women's Medical College at the infirmary. She took the chair of hygiene herself.