As the son of James Barbour (1828–1895), Barbour was a scion of the Barbour political family. Barbour was born on August 10, 1866 at Beauregard in Brandy Station, Culpeper County, Virginia. He was the son of James Barbour, a lawyer, planter, delegate from Virginia to the 1860 Democratic National Convention, delegate to the 1861 Virginia secession convention, and a major in the Confederate States Army during the American Civil War.
Barbour was educated at a private school and at William Hartman Kable"s Charles Town Male Academy in Charles Town, West Virginia.
His mother was Fanny Thomas Beckham. In 1884, Barbour began reading law at John Franklin Rixey"s law office in Culpeper, Virginia. In 1886, Barbour started a weekly newspaper, the Piedmont Advance, which operated for approximately two years.
Barbour then began attending law school at the University of Virginia in 1887 and graduated in 1888.
Barbour returned to Culpeper and joined Rixey"s law practice. Rixey was elected to the United States House of Representatives for Virginia"s 8th congressional district.
Barbour married Mary B. Grimsley on April 4, 1894. The couple had no children.
From 1897 through 1898, Barbour served as mayor of Culpeper.
Barbour was elected on May 23, 1901 to represent Culpeper County at the Constitutional Convention in Richmond, Virginia. At the convention on May 29, 1902, Barbour voted to proclaim the new constitution in effect without submitting it to the voters for ratification. Barbour relocated to Fairfax County, Virginia in 1907 where he joined R. Walton Moore and Thomas R. Keith to start up a law firm.
Barbour raised a dairy herd at his Fairfax County estate and founded the Maryland and Virginia Milk Producers Association.
While residing in Fairfax, Virginia, Barbour built the "Barbour House" which still exists today. Barbour died at Doctors Hospital in Washington, District of Columbia on May 6, 1952.
He was interred at Fairview Cemetery in Culpeper County, Virginia.
Served as private to 1st sergeant Culpeper Minute Men, 3d Regiment, infantry, Virginia National Guard. Member American, District of Columbia, Virginia State (national vice president), Fairfax Company bar associations. Clubs: Lawyers, University (Washington).
Married Mary Browning Grimsley, April.
