In the Saratoga campaign, Murphy is reputed to have shot and killed British Army officers Sir Francis Clerke and Simon Fraser.

His parents were Presbyterians from County Donegal, Ireland who moved to Shamokin Flats (now Sunbury, Pennsylvania) in 1759, when Murphy was eight years old.

[1] After this, Murphy was promoted to the rank of sergeant in the Continental Army's 12th Pennsylvania Regiment and fought at the battles of Trenton and Princeton.

"[citation needed] Murphy scaled a nearby tree, took careful aim at the extreme distance of 300 yards, and fired three times.

British senior officer Sir Francis Clerke, General Burgoyne's chief aide-de-camp, galloped onto the field with a message.

Several years after the 1807 death of his first wife, Murphy married Mary Robertson, and relocated to Charlotteville, New York, and thereby she had four more sons.