MASON, Armistead Thomson, (son of Stevens Thomson Mason), a Senator from Virginia; born at the “Armisteads,” in Louisa County, Va., August 4, 1787; graduated from William and Mary College, Williamsburg, Va., in 1807; engaged in agricultural pursuits; colonel of Virginia Volunteers in the War of 1812 and subsequently brigadier general of Virginia Militia; elected as a Democratic Republican to the United States Senate to fill the vacancy caused by the resignation of William B. Giles and served from January 3, 1816, to March 3, 1817; chairman, Committee on the District of Columbia (Fourteenth Congress); moved to Loudoun County, Va.; unsuccessful candidate for election in 1816 to the Fifteenth Congress in a campaign of much bitterness, which gave rise to several duels, and later resulted in his being killed in a duel with his brother-in-law, John Mason McCarty, at Bladensburg, Md., near Washington, D.C., February 6, 1819; interment in the churchyard of the Episcopal Church at Leesburg, Loudoun County, Va.