Mary Whiton Calkins (1863-1930) studied memory and developed the paired-associate technique in memory research. In her time, there was still a general and deep prejudice against women as students and professionals.
William James was instrumental in helping her to overcome sexist barriers when she was a student. However, even though she had completed all of the academic requirements for the PhD, Harvard refused to grant the degree to a woman, and continued to refuse her requests for many more years. Even so illustrious a person as James could not move Harvard on this issue.
Nevertheless, Calkins became professor at Wellesley College, where she set up the first psychological laboratory at Wellesley, carried out her research program, and authored several books, including two psychology texts (1901 and 1909). Calkins eventually became the first woman president of the American Psychological Association and by 1906 was considered one of the most important psychologists in the United States.