 He was born in 1726, in the city of New York, the son of James ALEXANDER, a fugitive from Scotland on account of his adherence to the house of Stuart.On the breaking out of the French war in 1755 young ALEXANDER became the aide-de-camp of General SHIRLEY, and he served in that capacity during the greater part of the war.In 1737 the earldom of Stirling became vacant, and on the death of his father, who made no claim to it although entitled to do so, William ALEXANDER preferred his claim, and in 1757 went to England to press his suit in person.