One of the six original programmers of the ENIAC, the first general-purpose electronic digital computer, Antonelli helped lay the foundations of modern computing.
Kathleen (Kay) McNulty was born on February 12, 1921, in Creeslough, County Donegal, Ireland. Her father, James McNulty, was a stonemason who had been active in the Irish Republican Army and was interned at the Curragh after the Easter Rising. The family emigrated to the United States in 1924, settling in Pennsylvania. She grew up speaking Irish as her first language and learned English only after the family's arrival in America.
She attended Chestnut Hill College in Philadelphia, where she was one of only three women to major in mathematics in the graduating class of 1942. After graduation, she was recruited by the U.S. Army to work as a human "computer" at the Moore School of Electrical Engineering at the University of Pennsylvania, calculating ballistic trajectories by hand using mechanical calculators. The work was painstaking and demanded exceptional precision. She and her colleagues processed thousands of differential equations to produce the firing tables that artillery crews depended on in the field.
In 1945, she was selected as one of six women to program the ENIAC (Electronic Numerical Integrator and Computer), which was being built at the Moore School under the direction of John Mauchly and J. Presper Eckert. The other five programmers were Jean Jennings Bartik, Frances Bilas Spence, Marlyn Wescoff Meltzer, Ruth Lichterman Teitelbaum, and Frances Elizabeth "Betty" Holberton. The women received no formal training and had to learn the machine's architecture by studying its logical and electrical diagrams. They developed the first programs to run on the ENIAC and demonstrated the computer publicly on February 15, 1946.
Kathleen McNulty married John Mauchly in 1948, becoming Kathleen Mauchly, and later, after John's death in 1980, she married Severo Antonelli and became Kathleen Antonelli. She continued to advocate for recognition of the ENIAC programmers' contributions, which had been largely overlooked for decades. Historian Kathy Kleiman's research in the early 1980s helped to bring the women's work to public attention. Antonelli gave numerous lectures and interviews in her later years, ensuring the historical record acknowledged the women's foundational role.
She received an honorary doctorate from her alma mater, Chestnut Hill College, as well as from the University of Pennsylvania. In 1997, she and the other surviving ENIAC programmers were inducted into the Women in Technology International Hall of Fame. She is sometimes called one of the mothers of modern computing. Kathleen (Kay) McNulty Mauchly Antonelli died on April 20, 2006, in Wyndmoor, Pennsylvania.
