Marie Charlotte Schaefer, the first female faculty member of the University of Texas Medical Branch, the third of five daughters of John Henry and Wilhelma (Butz) Schaefer of San Antonio, was born on June 24, 1874. She graduated from San Antonio High School as salutatorian in 1893 and taught for a year in the San Antonio public schools. In 1895 she entered the University of Texas Medical Branch, where she received an M.D. degree in 1900. Dr. Schaefer served as a resident in pathology at John Sealy Hospital in 1900–01, then became UTMB's first female faculty member. She was demonstrator of histology (1901–03), lecturer and demonstrator of histology (1903–10), and associate professor of biology and histology (1910–25). In 1925 she became the first female professor at the Medical Branch, a position she held until her death. One of her outstanding contributions to medical literature was the publication in 1901 of the results of her microscopic analysis revealing the presence of American hookworm in a Galveston patient. "Anchylostoma Duodenale in Texas" was published in Medical News. The research that led to this paper was undertaken with efficiency and strict method, qualities that the "old lady" consistently demanded of her hard-worked students. To faculty and personnel, however, she remained pleasant and gracious.
In 1912 Dr. Schaefer was asked to address the students and faculty at UTMB's opening session. She used this opportunity not only to inspire the students to a life of learning, dedication, and commitment, but also to pay homage to the struggles of earlier women who had opened the way for female medical, nursing, and pharmacy students. Schaefer was a member of the Texas State Medical Association, the American Medical Association, the American Association of Anatomists, the American Eugenic Society, and the American Association for the Advancement of Science. She also served on the Committee for Awarding Scholarships for Women of the George W. Brackenridge Loan Fund. On May 27, 1927, the day before annual commencement, she was taken ill while she was on campus and died before the day was over. The cause of her death was listed as acute heart disease. As a result of this sudden loss of one of UTMB's "oldest and most faithful servants," the final ball scheduled for that evening was canceled. Funeral services were held in both Galveston and San Antonio. She was buried in San Antonio, with former students serving as pallbearers, and was survived by her four sisters.