Hiram Gregory Berry was born in Thomaston (in an area now known as Rockland) in 1824. After working as a carpenter, a builder and a bank president, Berry served in the State Legislature and was elected Mayor of Rockland.

In 1853 Berry became lieutenant colonel of the Fourth Division of the Militia and in 1854 the company was mustered into the Volunteer Maine Militia. He became colonel of the 4th Maine Infantry at the beginning of the Civil War, and fought at the battles of Bull Run, Williamsburg and Fair Oaks, and was present at the siege of Yorktown. He was killed in the battle of Chancellorsville.

A gun battery named in his honor at Gerrish Island in Kittery Point was begun in 1873, but never finished.