He married in 1891 Annie Pitcairn, daughter of Harrington Robley, of Glasgow, by whom he had a family; but he was left a widower in 1909.
In the evening of the 18th of April 1775 a British force of about Boo men under Lieut.-Colonel Francis Smith and Major John Pitcairn was sent by General Thomas Gage from Boston to destroy military stores collected by the colonists at Concord, and to seize John Hancock and Samuel Adams, then at Parson Clarke's house (now known as the Hancock-Clarke House) in Lexington.
The expedition had not proceeded far when Smith, discovering that the country was aroused, despatched an express to Boston for reinforcements and ordered Pitcairn to hasten forward with a detachment of light infantry.
Early in the morning of the 19th Pitcairn arrived at the green in the village of Lexington, and there found between sixty and seventy minute-men under Captain John Parker drawn up in line of battle.
Pitcairn ordered them to disperse, and on their refusal to do so his men fired a volley.