George W. Rockwood was born on August 16, 1822, in Charlton, Massachusetts, to Samuel Rockwood and Susannah Harwood. He married Sarah Jane Pratt in Fitchburg, Massachusetts, on August 3, 1845, and they had at least two children: Charles, born around 1848; and Mary, born around 1866. Rockwood worked as a painter in Fitchburg.
He enlisted in the Union army on July 12, 1861, and mustered in as a captain in Company A of the 15th Massachusetts Infantry. Confederates captured him in the Battle of Ball’s Bluff on October 21, 1861, and he spent the next four months as a prisoner of war. He returned to his regiment in February 1862, and he took part in the Battle of Antietam and the Battle of Fredericksburg. He apparently resigned on January 28, 1863. He enlisted again on August 20, 1864, and mustered in as a sergeant in Company H of the 4th Massachusetts Heavy Artillery. He mustered out on June 17, 1865.
Rockwood returned to Fitchburg after the war, and the family moved to Sterling, Massachusetts, sometime in the late 1860s. He continued working as a painter, and by 1870, he owned $200 of personal property. By 1880, he was living in Marlborough, Massachusetts. He applied for a federal pension in 1882 and eventually secured one. He died in Waltham, Massachusetts, on April 18, 1896.