Definition of "darkey"

The windmill under the care of Mr. Kinney, a kind hearted old Englishman, was to me a source of infinite interest and pleasure. The old man always seemed pleased when he saw a troop of darkey little urchins, with their tow-linen shirts fluttering in the breeze, approaching to view and admire the whirling wings of his wondrous machine.

1855, Frederick Douglass, chapter 3, in My Bondage and My Freedom. […], New York, Auburn, N.Y.: Miller, Orton & Mulligan […]

Sometimes we overhear others saying, "Them colored people were slaves" down in Tennessee. The children feel hurt when they hear such remarks; but I tell them it was no disgrace in Tennessee to belong to Colonel Anderson. Many darkeys would have been proud, as I used to be, to call you master.

1865 August 7, Jordan Anderson, "To My Old Master, Colonel P.H. Anderson", republished in the New York Daily Tribune