Most notably, he wrote the New York Times bestseller, The Sands of Kalahari, which was later adapted into the movie by Paramount in 1965.
He completed boot camp at Fort Dix, New Jersey, and infantry training at Ft. Benning, Georgia.
However, Mulvihill was sent to Fort Bragg, North Carolina, to receive field artillery training before he could finish ASTP.
Due to his command of the German language and additional Army language training, he served as a forward observer with both the 78th Division and the 2nd Ranger Battalion during campaigns in the Ardennes, Rhineland and Central Europe, and experienced combat at the Battle of the Bulge, attaining the rank of Corporal and Squad Leader.
Upon his return to the United States, he completed his studies at Cornell, earning a bachelor's degree in German literature.
As an adjunct professor, Mulvihill also taught creative writing at Nassau Community and CW Post colleges.
He was a contributing editor to the Long Island Forum and a regular contributor to The Sag Harbor Express.
The Anna and Daniel Mulvihill Preserve, purchased by the Town of Southampton on March 26, 2003, was dedicated on June 15, 2001.
[7] Mulvihill, an admitted curmudgeon and "anti-growth fanatic" as well as known for being an ardent environmentalist,[8] wanted to see land remain as undeveloped as possible.
[14] On September 17, 2004, William Mulvihill died from pancreatic cancer in Glen Cove, Long Island, New York, at age 81.