Benjamin Franklin Buchanan was born 4 October 1859, at Plaster Cove Farm, Smyth County, Virginia. His parents were Patrick Campbell Buchanan and America Virginia Copenhaver. He studied at the University of Virginia where he got his BA degree in 1880 and his LLB in 1884. He was admitted to the Virginia Bar in 1885. He married Eleanor Fairman Sheffey in 1887. They had seven children: John Preston, Patrick Campbell, Josephine "Dee", Virginia Campbell Denit, Benjamin Franklin, Eleanor Fairman Starcher, David Hayter Buchanan.

In 1885 he founded the law firm of John A. and B. F. Buchanan with offices in Marion and Abingdon, Virginia. A year later his cousin John was elected to the Virginia Supreme Court and he continued practicing law with James L. White until 1912 when his son John Preston Buchanan joined the firm. Together they practiced corporate law at the renamed Buchanan and Buchanan law practice, until his death in 1932.

Buchanan served as general counsel to the Office of the United States Comptroller, Washington, DC (1915-1921). He was member of the Virginia Senate from the 1st District (1914-1916), representing Smyth and Washington counties; lieutenant governor of Virginia (1918-1922); member of the Virginia Senate from the 15th district (1924-1932), representing the City of Bristol, and Smyth and Washington counties.

Buchanan was member of the Phi Delta Theta Social Fraternity; member of the Virginia State Bar Association, American Bar Association; Blue Lodge Chapter, Masonic Order (Shriner, Knight Templar); member of the Westmoreland Club, Richmond; Army and Navy Club, Washington; Alfalfa Club, Washington; director of Marion National Bank, Bank of Marion, and First National Bank of Saltville; member of the Board of Visitors, University of Virginia; trustee, Marion Female College and Virginia State Normal School. Benjamin Franklin Buchanan died February 21, 1932 of a heart attack. (See: Winters, Marvin Eugene: Benjamin Franklin Buchanan 1859-1932 thesis. Box 3)