Orlando Chamberlain was born around 1844 in Farmington, Pennsylvania, to Nelson and Dimis Chamberlain. His father was a farmer who owned $200 of personal property by 1860. The family lived in Farmington until the 1850s, when they moved to Cameron, New York.
He enlisted in the Union army on May 18, 1861, and he mustered in as a private in Company E of the 34th New York Infantry on June 15, 1861. In December 1861, he declared that “I never will turn my back to the enemy of our Country.” It was “far better [to] lay my bones to bleach on the Batle field then have that good flag of ours disgraced and dishonored.” The regiment took part in the Peninsula campaign, the Seven Day’s Battles, and the Battle of Antietam. He was wounded in the left foot at Antietam on September 17, 1862, and he mustered out on April 20, 1863. He applied for a federal pension in May 1863 and eventually secured one.
He returned to the Union army on December 28, 1863, as a corporal in the 14th New York Heavy Artillery. The regiment took part in the Overland Campaign, the siege of Petersburg, and the Appomattox campaign. Confederate forces captured him at Petersburg on July 30, 1864, and imprisoned him at Danville, Virginia. He mustered out on May 29, 1865.
He married Mahala Bascom around 1863, and they had at least six children: Annette, born around 1864; Charles, born around 1866; Euphemia, born around 1869; Corwin, born around 1875; Lura, born around 1877; and William, born around 1886. They lived in Alma, New York, and Chamberlain worked as a farmer. By 1870, he owned $100 of personal property. They moved to Hampden, Ohio, in the 1880s. He died in Chardon, Ohio, on April 30, 1919.