McMurtry was born in Mercer County, Kentucky. William's parents were James and Elizabeth (Lucas) McMurtry. His great-grandfather, John McMurtry fought in the American Revolution, dying in the Battle of Cowpens. He and his family settled in Crawford County, Indiana in 1818. It was here that William married Ruth Champion (also of Mercer County, Kentucky), on November 23, 1826. In 1829, William and his young family moved to Knox County, Illinois along with his father and brother James and his wife. It was here that William McMurtry's home remained until his death.
During the Black Hawk War, McMurtry organized a group of between 70 and 90 men from Knox and Warren counties — which consisted of nearly all the able-bodied men from the area — to form a company of mounted rangers with him serving as captain and his brother James serving as sergeant. At the outset of the Civil War, he organized and led as colonel the 102nd Illinois Infantry, which was made up of men from Knox County. William McMurtry though only served a couple of months before receiving an honorable discharge due to poor health attributed to his advanced age.
At home, McMurtry was known as a bright man, despite only modest formal education, who was an avid reader and good neighbor. William was a Freemason and treasurer of the local Grand Lodge. He and his wife Ruth had five children. William McMurtry died in Henderson, Illinois; a town founded near his farm home after he and his family had settled there.
