George Floyd Harlan was born on May 26, 1842, in Bond County, Illinois, to William and Nancy Harlan. His father was a farmer who owned $7,000 of real estate and $1,200 of personal property by 1860. He grew up and attended school in Bond County, and by 1860, he was working as a farm laborer.
He enlisted in the Union army on August 23, 1861, and he mustered in as a private in Company C of the 26th Illinois Infantry. According to his service records, he was 5 feet, 11 inches tall, with black hair and dark eyes. He was promoted to corporal on September 1, 1862.
He settled in Beaver Creek, Illinois, after the war, and he married Mary E. Baldridge on September 12, 1865. They had at least ten children: Harriet, born around 1866; Emma, born around 1868; Charles, born around 1871; Nannie, born around 1872; Lou, born around 1872; Mead, born around 1876; Claud, born around 1879; Wallace, born around 1882; Maud, born around 1885; and Lois, born around 1890. He worked as a farmer, and by 1870, he owned $3,000 of real estate and $975 of personal property. By 1900, he was living in Mills Township, Illinois. He died there on July 14, 1914.