His ancestors on both sides settled in Virginia prior to the American Revolutionary War (1775–1783).

His father was one of the early pioneer settlers of Fayette County, Kentucky where they moved in 1797 and where Abernathy was raised.

[3][2][4] He was the father of Nancy Harrison Abernathy who married Dr. Hugh James Glenn, a wealthy California rancher and politician.

The town was laid out by Abernathy, James C. Fox, and E. W. McBride, and in 1837, contained seven stores and a number of families.

He went before Judge Jack Gordon and was admitted to the bar in early 1831 when he was thirty-six years of age.

[12][2][4] In 1831, Abernathy was the first appointed Treasurer of Monroe County and held that office for 12 years until he became district attorney in 1843.

In 1837, he laid out and dividing 40 acres of land in the town into 90 lots, which he sold for $1,100 (equivalent to $30,570 in 2024).

He won the election and was re-elected a second term by Governor Thomas Clement Fletcher.

[4] Abernathy died at his home in Paris, Missouri on January 29, 1886, at the age of 90 years.