Mary Ann Allard Booth (1843–1922): America's First Woman Microscopist

America's first professional female microscopist (Figure 1).She began explorations in microscopy in 1877, maintained a sales catalog of skillfully mounted microscope slides for over thirty years, and gained respect as a proficient photomicrographer among her colleagues.Booth's knowledge of microscopy led her to become the microscopy section editor for the magazine The Observer and Practical Microscopy [1].She was also a regular contributor to The American Monthly Journal of Microscopy, beginning with its first issue in January 1880.In 1889, she was elected to the executive committee of the American Microscopical Society [2].Mary Ann Booth traveled about the northeastern United States and Canada, lecturing about photomicrography, illustrating the presentations with projected lantern slides of her making.Most often, she was a guest of scientific societies, where she exhibited trays of microscope slides from her sales catalog (Figure 2).Mary Ann Booth was also a member of the American Association for the Advancement of Science and regularly attended its conferences.Internationally, Booth was elected a fellow of England's Royal Microscopical Society and the Royal Photographic Society of London [3].Few women of her time can claim standing in these nineteenth-century male-dominated organizations.At the 1884-1885 New Orleans World Industrial and Cotton Centennial Exposition, Mary Ann Booth was honored with a bronze plaque for her high-quality entomological microscope slides.At the St. Louis Exposition in 1904, she received a Medal of Accomplishment for working to advance the field of microscopy [4,5].The high quality of Mary Ann Booth's slides still captures recognition in the demanding environment of contemporary microscopy.In 2019, Mary Ann Booth's slide of cleaned Polycystina tests (cage-like structures) from Barbados won an honorable mention in Nikon's Small World International Photomicrography Competition (Figure 3).Mary Ann Booth considered a photomicrograph of a flea to be her most publicly notable achievement.During an interview with the Boston Globe, she stated that the flea picture was sent to U.S. Surgeon General Rupert Blue in 1910 while he was in California working to forestall another outbreak of bubonic plague.Blue used Booth's flea photograph in a government brochure to educate the public about rats, sanitation, and bubonic plague (Figure 4).Mary Ann Booth signed the back of the photograph along with comments written in her hand.The