Born in Rutherford College, North Carolina, Abernethy attended local public schools in Rutherford College before moving to Beaufort, North Carolina in 1893.

Abernethy studied law at the University of North Carolina at Chapel Hill and was admitted to the bar in 1895.

Practicing law in Beaufort, he was solicitor of the third (later the fifth) judicial circuit for twelve years, and a member of the executive committee of the North Carolina Democratic Party between 1898 and 1900.

Abernethy moved to New Bern, North Carolina in 1913, and continued to practice law there.

[1] He was a cousin to North Carolina's first Poet Laureate Arthur Talmage Abernethy.