Andrew Barclay was born in Albany in 1719. He was a younger son of Reverend Thomas and Anna Dorothea Drayer Barclay. He grew up with two brothers and Dutch-speaking mother in an Albany Anglican parsonage where his father's mental health was on the decline. Following the death of his father in 1726, this middle child was sent downriver to learn business.

In 1737, eighteen-year-old Andrew Barclay married Helena Roosevelt of New York City. The marital connection helped him become a Wall Street merchant and the father of five sons and six daughters who married into the upper levels of Anglo-New York society.

Son and brother of Anglican clerics, this Manhattan-based merchant was a known royalist whose involvement in the struggle for American liberties was curtailed by an early death in June 1775. His epitaph read "On Monday last, died Mr. Andrew Barclay, an eminent merchant and brother of the Rev. Dr. Barclay."