John Davis Long was born in Buckfield, Maine on October 27, 1838, to Zadoc Long and Julia Temple (Davis) Long.
He was named for Massachusetts Governor John Davis, a cousin of his maternal grandfather.
He received his primary education at Hebron Academy until attending Harvard University where he graduated Phi Beta Kappa in 1857.
At Harvard he was a member of the Delta Kappa Epsilon fraternity's Alpha chapter.
Long wrote both prose and verse for a student magazine, and was chosen to write an ode for his class's graduation.
He also began a private journal some time before his arrival at Harvard, which he maintained throughout his life.

After two years as headmaster of Westford Academy in Westford, Massachusetts, Long began attending Harvard Law School, becoming a member of the Massachusetts bar in 1861.
He practiced law, first without success in Buckfield, and then in Boston, and was active in the state militia during the American Civil War.
He moved to Hingham, Massachusetts in 1869, and the following year married Mary Woodford Glover of Hingham.
The couple had two daughters (and one stillborn birth) before her death in 1882.
John Davis Long was born in Buckfield, Maine on October 27, 1838, to Zadoc Long and Julia Temple (Davis) Long. He was named for Massachusetts Governor John Davis, a cousin of his maternal grandfather. He received his primary education at Hebron Academy until attending Harvard University where he graduated Phi Beta Kappa in 1857. At Harvard he was a member of the Delta Kappa Epsilon fraternity's Alpha chapter. Long wrote both prose and verse for a student magazine, and was chosen to write an ode for his class's graduation. He also began a private journal some time before his arrival at Harvard, which he maintained throughout his life.
After two years as headmaster of Westford Academy in Westford, Massachusetts, Long began attending Harvard Law School, becoming a member of the Massachusetts bar in 1861. He practiced law, first without success in Buckfield, and then in Boston, and was active in the state militia during the American Civil War. He moved to Hingham, Massachusetts in 1869, and the following year married Mary Woodford Glover of Hingham. The couple had two daughters (and one stillborn birth) before her death in 1882.
John Davis Long