William Thomas Fitzsimons was born on April 18, 1889, in Burlington, Coffey County, Kansas. He was the son of John I. Fitzsimons and Catherine G. Manson Fitzsimons. He graduated with a Doctor of Medicine degree in 1912. Following the U.S. entry into World War I, Fitzsimons volunteered for overseas service and was assigned as a First Lieutenant to Base Hospital No. 5 near Dannes-Camiers, supporting the British Expeditionary Forces.

On the night of September 4, 1917, during a German air raid on the hospital, Fitzsimons was killed when bombs struck the facility. He was initially buried in the British cemetery at Étaples but was later moved to Somme American Cemetery and Memorial, Bony, Departement de l'Aisne, Picardie, France.

Source of information: en.wikipedia.org