Born in West Caln township, Chester County, Pennsylvania, he was the son of William Addleman I and Mary Henecks (aka Hennix) of Chester County. His parents and his uncle Joseph's family moved to Wayne County, Indiana after the death of their father, John (Hans) Michael Addleman, in 1814. They migrated in stages during 1817 and 1828.

William grew up in a family that was steeped in military tradition. His father, all three of his father's brothers, and his grandfather served in the Revolutionary War.

William married Mary Elliott in Wayne County on December 31, 1835. She was a daughter of Job Elliott and native of North Carolina. They had six sons and three daughters.

The Addleman family's military tradition continued when four of William's sons and three of his nephews enlisted for the Union to serve in the Civil War.

Three of William's sons served in Colonel Meredith's regiment (19th Indiana Infantry). This regiment, the famed "Iron Brigade of the West", fought in the major battles in the eastern theater and had the highest casualties proportionately compared to all other regiments in the Civil War. Only one of his three sons serving in this regiment survived the war.

William and Mary's children were:

John H. Addleman, (1836-1928), fought in the Civil War; survived.

Mary E Addleman (b. 1839)

Jacob O. Addleman (1840-1862), fought in the Civil War; died from disease.

Joseph O. Addleman (1842-1862) fought in the Civil War; killed at the Battle of Antietam.

Margaret G. Addleman (b. 1844)

William Oberline Addleman (1846-1915), fought in the Civil War; survived.

Nathan G. Addleman (b. Aug. 1850)

Charles J. Addleman (b. 19 Mar 1852)

William's wife preceded him in death on April 22, 1870. He lived to be 82 years of age and died in Wayne County, Indiana.