George S. Palmer was born around 1838 in Connecticut to Elliot and Florilla Palmer. His father was a Congregationalist minister who owned $3,500 of real estate and $1,300 of personal property by 1860. The family lived in Stafford, Connecticut, until the 1850s, when they moved to Newark, New Jersey. By the early 1860s, Palmer was working as a farmer in Cromwell, Connecticut.
He enlisted in the Union army on August 13, 1862, and he mustered in as a private in Company D of the 20th Connecticut Infantry on September 8. The regiment took part in the Battle of Chancellorsville, the Battle of Gettysburg, the Atlanta campaign, the March to the Sea, and the Carolinas campaign. He fiercely opposed the enlistment of African American soldiers, declaring it “one of the greatest curses that ever befell our once happy country.” In August 1863, he wrote that he was “sick of the war.” If the “Abolitionists of the north and the southern fire eaters look in our hospitals and over the land,” he wrote, “I think we would have peace that would do justice to both sides.”
The following month, he added that “Copperheads and Abolitionists will not find much favor when the soldiers come home.” Nonetheless, Palmer remained devoted to the Union. In September 1863, he prayed that "this cruel and unjust Rebellion may end and that we may live to once more enjoy the benefits of liberty and justice through our noble land." In March 1864, he denounced Confederates as “the destroyers of our country and our flag.” He supported President Abraham Lincoln in the election of 1864. As he explained to his parents, "I hope that Mac [George McClellan] will be defeated[.] I prefer old Abe to run the machine for four years longer[.] the prisoners cheer for little Mac and that goes against the grain of any soldier that loves his flag and country." He mustered out on June 13, 1865.
Palmer moved to Portland, Connecticut, after the war, and he resumed his work as a farmer. He married Elizabeth Bailey, and they had at least four children: William, born around 1872; Frederick, born around 1879; Gertrude, born around 1885; and Frances, born around 1887. He lived in Portland until at least 1910, and he died in 1912.