Born in Waynesboro, Virginia, to the former Sarah Jane Garber and her husband Lewis Harman (1794-1840), his father died when he was 16 years old.

His maternal grandfather, John Cunningham, had been a member of Staunton's Committee of Safety in the American Revolutionary War, as well as captain of a cavalry company in the Virginia militia.

William H. Harman, a prominent local lawyer, would begin the war as a Brigadier General of the Virginia militia and helped secure the Harper's Ferry arsenal immediately after secession.

Harman would become a Lieutenant in the Staunton Artillery of the Confederate States Army, but die in September 1861 of typhoid fever in Prince William County, Virginia.

During the Mexican–American War, he abandoned the press, and fought as a member of Hays' Texas Rangers in Captain Gillespie's company.

[5] Meanwhile, another brother, William Henry Harman (1828-1865), a Texas war veteran, became a prominent lawyer in Staunton and the commonwealth's attorney.

Although Augusta County was a Whig stronghold, Harman was an active Democrat, noted for his efforts in the struggle against the Know Nothings.

Despite Jackson's appreciation of Harman's talents as supply and transport officer, the relationship between the two men was not smooth.

"[13] During Jackson's Valley Campaign, Harman received 48 hours leave because his children were sick with scarlet fever.