James Sterling (sometimes "Stirling") was born in Ireland and came to North America in the early 1750s. He served as an officer in the Pennsylvania forces during the French and Indian War, and as commissary of provisions at Fort Oswego in 1759 and Fort William Augustus in 1760. In July of 1761, Sterling relocated to Detroit, where he became the western agent of the trading firm Livingston, Rutherford, Duncan, Coventry & Syme. Sterling was a shrewd businessman, proficient in English, French, and several Native American languages, and quickly found success in this role. The firm dispatched goods and merchandise to other traders in New York and to the upper Midwest, and supplied goods for cash to British forts at St. Joseph, Bay City, and Michilimackinac, as well as to the British and French civilians around those posts. During Pontiac's siege of Fort Detroit in the summer of 1763, Sterling commanded the local militia. The next year, he formed a trading partnership with John Duncan, which John Porteous joined several years later. On February 9, 1765, Sterling married Angélique Cuillerier, dit Beaubien, who had grown up in a family of prominent traders and spoke several Indian languages. They had at least three children: Jacques, Angélique, and Pierre.
Sterling also found work as a tax collector and surveyor. He was assistant engineer under Henry Hamilton at Fort Detroit and surveyed land there shortly after the outbreak of the American Revolution. After a falling out with Hamilton, he went briefly to Quebec in 1778, and then returned with his family to England. There, he continued his business partnership with Porteous and was part-owner of the British privateer, Vengeance . Sterling is thought to have returned to North America after the war, but the date and place of his death are unknown.