Dr. Josephine Walter was educated in the private school conducted by Madame Mears in New York City, and after her graduation, with the active encouragement of her family physician, the celebrated Dr. Willard Parker, and of Dr. Abraham Jacobi, she determined upon the study of medicine. To that end, she matriculated at the college of the New York Infirmary for Women, and while a student there, obtained special permission to attend the lectures of Professor Ogden N. Rood, professor of physics at Columbia College, becoming thereby the first woman student ever to attend Columbia. Upon her graduation from medical school, she competed for and won a position on the house staff at Mount Sinai Hospital in New York, being the first woman so appointed in the United States.
She spent three years in hospital service and then went abroad to continue her studies. In 1888 she returned to New York and entered active practice, devoting her special attention to the treatment of the diseases and ailments of women.Dr. Walter was also a lecturer for many years at Mount Sinai Hospital Training School for Nurses. At the entry of the United States into the World War, she organized a complete unit of woman doctors, with the permission of the War Department, for service overseas, but this detachment was never sent abroad.
Dr. Walter was a contributor to over fifty charities. She was a member of the American Medical Association, the New York Academy of Medicine, and the Mount Sinai Alumni Society.