William Styer was born on November 25, 1832 in Delaware County, Ohio to Joseph Tyson and Rachel (Kedney) Styer. He married Susannah Defenbaugh (also spelled Defabaugh and Dieffenbach) on May 4, 1858 and the couple had two children, Charles A. and Carrie M. Styer. William Styer worked as a schoolteacher and as a grocer in Kokomo, Indiana.

On August 9, 1862, Styer was commissioned as a Second Lieutenant in Company D of the 89th Regiment of Indiana Volunteers. He mustered in on August 28, 1862 in Indianapolis and the regiment was sent to Fort Pickering in Memphis, Tennessee, where they performed guard and fatigue duty from December 21, 1862 to October 18, 1863. In March of 1863, Styer was placed in command of the Memphis military prison, which held Confederate prisoners of war, deserters, and civilians charged with crimes. He resigned his commission on October 20, 1863 because of disability and returned to Kokomo.

Between 1863 and 1881, Styer sold groceries and quarried stone. In 1881, he took charge of Spring Mills in Kokomo. He died on February 8, 1890. It should be noted that there is some debate over Styer's exact date of death. February 8, 1890 has here been accepted as authoritative on the grounds that Susannah Styer was granted a widow's pension on July 9, 1890, thus indicating that William Styer died prior to this date and so well before all other proposed death dates.