Florence Sabin entered Smith College in the fall of 1889, joining her sister Mary. Fascinated by a freshman year zoology course, she decided to major in science. She was not attracted to a career in teaching, one of the few professions open to educated women at that time, so, in her junior year, she consulted Smith's resident physician, Dr. Grace Preston, about pursuing medicine. Preston encouraged her, noting that women who attended medical school were also striking a blow for women's rights in America. An especially interesting situation was developing in Baltimore just then, Preston told Sabin: the trustees of Johns Hopkins University were trying to raise enough money to open the university's long-delayed medical school. A group of influential wealthy women had offered to supply the crucial funds, with several conditions. First, all students admitted would be required to have an undergraduate degree, and pass rigorous entrance exams. Second, women would be admitted on the same basis as men. Should these conditions be accepted by the trustees, as seemed likely, Johns Hopkins School of Medicine would not only offer a first-rate medical education, but would offer it to women. Preston recommended that Sabin apply to Johns Hopkins as soon as it opened.
When Sabin approached her father and sister with this plan that summer, they told her the family could not afford medical school, and suggested she become a schoolteacher, as Mary had. Following her graduation from Smith College in 1893, Sabin did indeed teach school, but only until she had saved enough to carry her through her first year at Johns Hopkins. She returned to Colorado and taught high school science in Denver for two years, and during that time met Mrs. Ella Strong Denison. Denison was a wealthy young matron who was so impressed with Sabin's teaching that she invited her to tutor her children during the summer of 1894. Sabin's affectionate association with Mrs. Denison, her children, their cousins, and grandchildren would last the rest of her life. Mrs. Denison took a maternal interest in Sabin, sending household gifts and occasional spending money during Sabin's student years, and opening her home to Sabin and her sister during vacations. In 1923 Denison surprised her young friend by sending a large check with which to buy a car. (Sabin's choice was a Franklin, which she named the "Susan B. Anthony" after the women's suffrage leader.) For the 1895-96 school year, Sabin returned to Smith College as a substitute instructor. She then spent the summer at the Biological Laboratory at Woods Hole, Massachusetts, before starting her medical training in September 1896.
The Johns Hopkins School of Medicine opened in 1893. Like Johns Hopkins University, it was modeled on the best German institutions, which gave high priority to individual research and interaction with faculty, and encouraged students to pursue knowledge for its own sake, rather than learning by rote, as was the tradition in many American colleges and medical schools. Its four-year medical program and high admissions requirements were major innovations in American medical education at the time. Although it had very high standards and admitted women on the same basis as men, there were no female professors, and men students greatly outnumbered the women. The best research projects and limited number of hospital internships--essential for gaining clinical experience--almost always went to the men. Even enlightened medical professors assumed that most women medical students would eventually marry and leave the profession. Male medical students sometimes resented their female colleagues. One of the remarkable things about Florence Sabin was that the many small slights and inequalities did not bother her. She loved her medical coursework, especially the laboratory classes, and had complete confidence that women could achieve whatever they were willing to work for.
Impressed by Sabin's serious approach and intelligent questions, Dr. Franklin Mall, chair of the Anatomy Department, became her mentor, her role model for both scientific work and teaching. Like most of the Hopkins medical faculty, Mall had done postdoctoral work in Germany, training with some of the best scientists of the age, including physiologist Carl Ludwig, and embryologist Wilhelm His. Mall continued to be an active researcher at Hopkins, and was devoted to developing medical science in America. To this end, he worked to get able students (though he believed them to be rare) into research, and then get them the free time, facilities, and faculty guidance they required. In directing students' research, Mall gave them the greatest possible freedom to choose their problems, and to enjoy their discoveries. For Sabin's first serious research project, Mall suggested that she study the origins of the lymphatic vessels that drain fluids from body tissues. At that time, the lymphatic system still puzzled anatomists. Some investigators believed that these vessels derived directly from the mesenchyme, the undifferentiated connective tissue in the embryo, from which connective tissues, blood vessels, and other structures develop. They also believed that the lymph channels were open, rather than closed. Sabin, by injecting colored substances into the lymph channels of animal embryos, eventually was able to show that lymph structures derived directly from the vein tissues, and were closed, not open. Sabin's innovative work on this and on another project suggested by Mall--modeling the brain anatomy of newborn humans--allowed her to publish several articles and a monograph by the time she finished her hospital internship year in 1901.
Franklin Mall's mentoring was crucial to Sabin's development as a medical scientist. However, her fledgling research career following medical school was launched largely with support from two women's groups: the Baltimore Association for the Promotion of University Education for Women funded a fellowship for a year of postdoctoral work with Mall in 1901. Her work that year earned her much praise from Mall and other colleagues, and a $1,000 prize from the Naples Table Association, a group dedicated to supporting women in science. Although the Johns Hopkins Medical School had previously resisted hiring any women to the faculty, Sabin's outstanding performance persuaded the trustees to hire her as an assistant instructor in 1902.
Florence Sabin was a trailblazer for women in science, and a firm believer in equal opportunities for women. During her time at Johns Hopkins, her friends included women physicians and women's rights activists. She helped them with letter-writing campaigns for the National Women's Party, and editorial work for a weekly suffrage newspaper. Between 1900 and 1910, she also donated her time to the Evening Dispensary for Working Women and Girls, and became good friends with the Baltimore women physicians who founded it. Only rarely, however, did she neglect her scientific work to march in suffrage parades. Throughout her life, her feminism would be expressed mainly by the example of achievement she set. She would never make gender an issue in her profession, nor would she mentor young women if they were not also serious and capable scientists.