David Duncan was born on the Sixth day of September, in 1772, at Carlisle, Cumberland, County, in the State of Pennsylvania. He was the son of William Duncan, who was born in 1728, at Hopewell Township, Cumberland County, in the State of Pennsylvania and Mary Albert, who was born in 1735, at Lancaster County, in the State of Pennsylvania.
David Duncan held the rank of Captain, in the in the American Army, in the War of 1812.
David Duncan was married to Letitia Anderson on the Eleventh day of April, in 1793, at Carlisle, Cumberland County, in the State of Pennsylvania. They were the parents of:
Elizabeth Duncan was born in 1894, at Cumberland County, in the State of Pennsylvania.
Letitia Duncan was born in 1794, at Cumberland County, in the State of Pennsylvania.
Mary Duncan was born in 1795, at Cumberland County, in the State of Pennsylvania.
William Duncan was born in 1797, at Cumberland County, in the State of Pennsylvania.
Ruth Duncan was born on the Eleventh day of January, in 1800, at Cumberland County, in the State of Pennsylvania and died on the Sixth day of March, in 1855, at Moro, Madison County, in the State of Illinois. She was married to Samuel Smith on the Thirteenth day of June, in 1820, at Cumberland County, in the State of Illinois. He was born in 1790, at Lancaster County, in the State of Pennsylvania.
John Duncan was born in 1800, at Cumberland County, in the State of Pennsylvania.
David Duncan was born in 1804, at Cumberland County, in the State of Pennsylvania.