William Whitaker was born around 1841, possibly in Kershaw County, South Carolina, to Lemuel L. Whitaker and Helen B. Muir. His father was a planter who owned $20,000 of real estate and $105,700 of personal property in 1860, including at least 46 slaves. Whitaker attended school in Kershaw County.
He enlisted in the Confederate army on September 21, 1861, and mustered in as a private in Company E of the Holcombe Legion's Cavalry Battalion. Whitaker was promoted to corporal on June 18, 1862, and to sergeant on February 1, 1863. In March 1864, the battalion became part of the 7th South Carolina Cavalry. The men helped defend Petersburg, Virginia, and they surrendered with General Robert E. Lee's army at Appomattox Court House on April 9, 1865.
Whitaker returned to Kershaw County after the war and began working as a farmer. The 1880 census described him as a "Planter," and listed him as living with his brothers and sisters in Kershaw County. He probably remained in Kershaw County for the rest of his life, and he died sometime after 1910.