Mary Anson Hennessy (b. 1943) served in the United States Army Nurse Corps from 1966 to 1968. Mary Anson Hennessy was born 22 August 1943 at Fort Leavenworth, Kansas. As a result of her father's involvement with the United States Army, she spent her adolescence at various military bases, including two of his deployments to Japan when she was ages five and thirteen.

After graduating from high school in 1961, Hennessy worked for a year with a group of lay missionaries under the guidance of Father Vincent S. Water of the Raleigh, North Carolina diocese of the Roman Catholic Church. While taking night classes at Donnelly College in Kansas City, Missouri, Hennessy decided to pursue a career in nursing. She began nurses' training at Saint Mary's School of Nursing, where she had rotations in obstetrics, psychiatry, and pediatrics.

In 1965, during her senior year of nurses' training, Hennessy decided to join the United States Army Nurse Corps, and was sworn in for two years of service. Hennessy attended basic training at Fort Sam Houston, Texas, in 1966, and was posted to the same base after her graduation. She was assigned to Brooke Army Medical Center there, where she worked primarily on the orthopedic ward.

In 1967 she volunteered to serve in Vietnam, but illness forced her to convalesce stateside. She was eventually sent to Fort Leonard Wood, Missouri for her second duty station. Hennessy married her high school sweetheart 3 August 1968, and as a married woman could no longer serve in the Army Nurse Corps, so she retired soon after. She subsequently became pregnant, and had her first son in May 1969.

In the mid-1990s, Hennessy, pursuing her love of Shakespeare, received a scholarship to attend North Carolina State University. She graduated in 2000 with a Bachelor of Arts in English.