Background
Blackwood was the eldest son of Sir John Blackwood, 2nd Baronet, and Dorcas Stevenson, later Baroness Dufferin and Claneboye.
Blackwood was the eldest son of Sir John Blackwood, 2nd Baronet, and Dorcas Stevenson, later Baroness Dufferin and Claneboye.
He was returned to the Irish Parliament for Killyleagh in 1776, a seat he held until his death ten years later. He died in Belfast in June 1786, after a fall from his horse.