Identity:
The C. H. Tweed mentioned in Whistler's correspondence was an American art collector.
Life:
He may have been the New York lawyer, Charles H. Tweed (b. ca 1840) from Maine, who was Counsel for the Central Pacific Rail Road Company in 1886. It is possible therefore that he could have known the Whistler and/or WInans family, who had considerable interests in railways and railway companies.
Bibliography:
UK census 1880; New York Public Library on-line catalogue at http://catnyp.nypl.org (accessed 2005).