George J. Whiteman was born on April 2, 1834, in New York to Peter and Sarah Whiteman. He eventually moved to Harrison, Pennsylvania, and he married Ruth Hackett around 1860. They had at least five children: George, born around 1862; Lewis, born around 1868; Nelson, born around 1869; Cynthia, born around 1874; Alice, born around 1878.
He enlisted in the Union army on October 29, 1861, and he mustered in as a private in Company G of the 53rd Pennsylvania Infantry. The regiment took part in the Peninsula campaign, the Seven Days’ Battles, the Second Battle of Manassas, the Battle of Antietam, and the Battle of Fredericksburg. He was discharged on January 31, 1863. He rejoined the Union army in February 1864, mustering in as a private in the 2nd Pennsylvania Cavalry. He later served in the 2nd Veteran Reserve Corps Battalion. He mustered out in September 1865.
He returned to Harrison after the war, and he earned a living as a farmer. He applied for a federal pension in September 1865 and eventually received one. By 1870, he owned $1,500 of real estate and $650 of personal property. He died of heart disease in Harrison on February 6, 1917.