The annual report of births to the Kentucky state auditor lists William Stephens, born 14 Dec 1859, father Richard Stephenson, mother’s maiden name Sarah Ellington.

The death of his mother, though, is recorded as being on 22 Jan 1859, so one of the dates must be wrong. Considering that he was listed as age 1 in 1860, most likely either he was born in Dec 1858, or Jan 1859. (The other possibility is that Sarah did not die until Jan 1860, but if that were the case, then William should have been listed as only 8 months old in the 1860 census.)