Born: April 4, 1810, Hanover, New Hampshire.
Died: June 8, 1888, Jamaica Plain, Boston, Massachusetts.
Buried: Forest Hills Cemetery, Jamaica Plain, Massachusetts
Clarke graduated from Harvard College (arts, 1829; divinity, 1833). He, Oliver Wendell Holmes and Samuel Smith were in the same class at Harvard.
After being ordained a Unitarian minister, he served pastorates in Louisville, Kentucky (1833–40); and at the Church of the Disciples, Boston, Massachusetts (1841–50), and from 1854 until his death.
While in Louisville, he edited for a while The Western Messenger.