His brother, Philip P. Barbour, would later become Speaker of the United States House of Representatives and Associate Justice of the Supreme Court.

His friend and neighbor at Monticello plantation, Thomas Jefferson, helped design the mansion in which Barbour lived most of his adult life, called Barboursville.

Orange County voters elected Barbour to the Virginia House of Delegates in 1796, and he became that body's youngest member.

In the House of Delegates, Barbour took pride in writing the bill establishing the Literary Fund of Virginia, passed on February 2, 1810.

Barbour later requested that the only inscription on his tombstone be a reference to this Act,[6][7] affirming his firm belief that society would progress only through education.

At the time, British raiders were impressing American sailors (including Virginians, especially near Hampton Roads and Norfolk).

Governor Barbour sought funding for Virginia's militia on February 11, 1812, and personally toured the tidewater region most at risk.

Perhaps because of his wartime preparations (or willingness to risk his funds), Barbour faced no opposition and was reelected Governor in November 1812.

Some delegates opposed Barbour's support of President James Madison and national unity but nonetheless reelected him.

Barbour also authorized exploration of the upper James River and received funding to improve Virginia roads.

Senator Barbour also opposed reducing the national army, supported a bill abolishing imprisonment for debts, and introduced the Navigation Act of 1818.

His speech may have foreshadowed the Southern position in the American Civil War after his death: Sir, no portion of the Union has been more loyal than the South.

But the moment you pass that Rubicon, they will redeem their much abused character and throw back upon you your insolence and your aggression.As Senator, Barbour sponsored a resolution giving an honorary sword to Colonel Richard Mentor Johnson of Kentucky for his efforts in the Battle of the Thames in 1813.

Virginia legislators elected the Jacksonian Democrat John Randolph of Roanoke to succeed Senator Barbour in December 1825.

Barbour soon came into conflict with Governor George Troup of Georgia, who wanted to evict Creek Indians from 5 million acres (20,000 km2) of land.

Governor Troup's partially-Creek cousin William McIntosh had signed the Treaty of Indian Springs (1825), purporting to relinquish tribal lands in exchange for $200,000 for himself and installments totaling $200,000 for five other signatories.

The U.S. Senate approved it by one vote on March 7, but tribal members protested vehemently, sentenced McIntosh to death, and killed him.

Both treaties provided for removal west of the Mississippi (as President Jackson would later do the Cherokee Indians on the Trail of Tears).

[8] By 1826, President Adams was deeply unpopular compared to his opponent in 1824 (and presumptive in 1828), Andrew Jackson, as was Secretary of State Clay.

During the 1820s, Barbour was a member of the Columbian Institute for the Promotion of Arts and Sciences, as were other prominent military and medical professionals.

After President Adams' electoral defeat in 1828, Barbour returned to Virginia, announcing his candidacy for the General Assembly.

Barbour presented an imposing appearance, with a striking face, long, shaggy eyebrows, and head covered with silvery flowing locks; with a majestic and sonorous voice, he filled one's conception of a Roman Senator in the last days of the Republic.

[11] The Barbour family remained politically powerful in that area of Virginia for the rest of the century, despite no longer enslaving people after the American Civil War.

His first cousin John S. Barbour (1790–1855) also served in the Virginia General Assembly and chaired the Democratic National Convention of 1852.