His father, William Ferguson, was a shipmaster of that port, and his mother, Mary, was the only daughter of John Service of Holms of Caaf, a small property near Dalry, Ayrshire.
The father of Mary Service followed this profession, and was a man of penurious habits and peevish temper.
Ferguson was educated at Ayr, was for some time in a banker's office, went to America in connection with the affairs of one of his uncles, returned after four years, and in 1810 settled with his mother at Irvine.
Ferguson, by his sagacity and knowledge of the money market, increased the fortune, till at his death it amounted to 1,247,514l.
He was a man of somewhat ordinary character, undecided, was never married, and for the last few years of his life lived in comparative seclusion.
After consulting with Mr. John Henderson of Park, a well-known merchant of Glasgow, who was his intimate friend and acted as his private banker, and Mr. Matthew Montgomery of Kelvinside, he devoted the residue of his property, after providing for family legacies and making other provisions, to the objects of what is known as the Ferguson Bequest Fund.