Hiram Berry was born on August 27, 1824, in Thomaston (now a part of the city of Rockland), Maine, United States. His parents were Jeremiah and Frances (Gregory) Berry. He came of fighting stock, as his grandfather was a soldier of the Revolution, and his father a veteran of the War of 1812.
Berry began life as a carpenter, but rose to be a builder and a business man, and president of a bank. Having been a captain of militia before the Civil War, at its beginning he was chosen colonel of the 4th Maine. He led this regiment, and afterward a brigade, and finally a division in the Army of the Potomac, and served from the first battle of Bull Run until his death. He was commissioned brigadier-general of volunteers March 17, 1862, and commanded a brigade in General Kearny's division during the Peninsula campaign. He was particularly distinguished at the battles of Williamsburg (May 5) and Fair Oaks (May 31-June 1, 1862), and was commended by the division commanders Kearny and Hooker, by the corps commander Heintzelman, and by McClellan.
Suffering from injury and ill health, Berry was on furlough at Rockland, but returned in time for the battle of Fredericksburg, having been commissioned major-general of volunteers November 29, 1862. A picturesque incident is related in regard to this battle: the Confederate general, A. P. Hill, is said to have presented his compliments to Berry, with the remark that his command was the "best behaved brigade that he ever saw under fire. " In February 1863, after Hooker had succeeded Burnside in command of the Army of the Potomac, Berry was promoted to a division (formerly Hooker's division) in the 3rd Corps. As general of this division he had an important part in the battle of Chancellorsville, May 2 and 3, and was killed in the crisis of the struggle.
Berry was a Democrat in politics, a member of the legislature, and one of the early mayors in the new city of Rockland.
Berry was a plain, straightforward man, tall and broad-shouldered. His blue flannel blouse and his whole dress gave him very little of a military air. But whoever judged him from his appearance would have judged badly he was not the less a good officer, as faithful to his duty as he was devoted to his soldiers. In him the moral energy strove against physical weakness.
