George William Agnew was an art dealer and publisher. He married Fanny Bolton and they had two sons and five daughters. His son Colin went into the family business of Thomas Agnew & Sons.
An exhibition in Manchester in 1887 is the only known contact between Whistler and Agnew.
'Sir George Agnew', The Times, London, Saturday, 20 December 1941, p. 6.
'Thomas Agnew & Sons', Wikipedia.
'Thomas Agnew & Sons' in Archives Directory for the History of Collecting in America, The Frick Collection.