Dr. Edna Schneider Hoover (1926 - ) is an American mathematician who invented the computerized telephone switching system. She grew up in New Jersey, fond of the outdoors and traditionally boys’ sports; she became interested in science at an early age and was inspired by Marie Curie’s biography. She received a BA from Wellesley College in medieval history in 1948 before pursuing her Ph.D. at Yale in the philosophy and foundations of mathematics. Her 1951 dissertation was titled “An Analysis of Contrary-to-Fact Conditional Sentences,” a study of logic. She taught for a few years at Swarthmore College before relocating to New Jersey for her husband’s job. She was then hired as a researcher at Bell Laboratories in 1954. Bell Labs was just beginning to explore the development of electronic switching systems, to improve the telephone’s ability to take more phone calls. She was quite qualified for this task, and in fact, while recovering from giving birth to her second child, she created the ESS system which eliminated the danger of overload in processing calls, and for which she received a software patent in 1971. She was promoted as the first woman to Technical Department Head at Bell Laboratories in 1978. Hoover retired from Bell in 1987.