John Leavitt Stevens was born in 1820 in the town of Mount Vernon, Kennebec County, Maine, to Capt. John Stevens and Charlotte (Lyford) Stevens. He was a lifelong resident of Augusta in the same county, except for his time away at school and his later diplomatic service. Stevens attended Maine Wesleyan Seminary to prepare for a minister's career in the Universalist church, which he served as pastor for a decade, becoming a leader in the anti-slavery movement. (Stevens later became a firm opponent of capital punishment, and as a Maine State Senator urged the legislature to abolish the death penalty).