
Fighting Peacocks dates from 1877. It is on the verso of drafts of letters to Frances Leyland (1834-1910) and Frederick Richards Leyland (1832-1892), dating from July 1877. 1
The draft letter to F. R. Leyland reads:
‘Your son dined with me at my own table since the visit in question of Tom Leyland and myself at Princes Gate - and I returned with your son at his request to his mother’s house where I passed the evening - since then I have been honored with many courteous invitations transmitted through him to me
Theatrical in your threat - Ridiculous in your rage - Fuming in your frill, I refer you to the Cartoon opposite you at dinner, known to all London as “L'Art et l'Argent” or the Story of the Room -’ 2
It is not known whether Whistler sent such letters. The drafts were written on the first two sides of a folded sheet, and the rough sketch is on the back.

Fighting Peacocks, Glasgow University Library
For once, the subject of the letter and of the drawing are clearly related, and the sketch must date from when Whistler was working on his panel of the fighting peacocks (see Cartoon of rich and poor Peacocks m0584) or immediately afterwards.
The drawing is fully catalogued in MacDonald 1995 (cat. rais.) [more] (cat. no. 583).

Fighting Peacocks, Glasgow University Library

Harmony in Blue and Gold: The Peacock Room, south wall, Freer Gallery of
Art

Harmony in Blue and Gold: The Peacock Room, south wall, Freer Gallery of
Art
The completed panel, for which this is a study, was put up on the south wall of Harmony in Blue and Gold: The Peacock Room y178, which was the dining room in the Leyland's house 49 Prince's Gate, London. It was taken down and re-erected, first in Detroit and then in the Freer Gallery of Art in Washington, DC.

Fighting Peacocks, Glasgow University Library

Harmony in Blue and Gold: The Peacock Room, south wall, Freer Gallery of
Art
This is a study for, or sketch of, the panel of fighting Peacocks in Harmony in Blue and Gold: The Peacock Room y178.
A very rough sketch indeed.
The sheet was folded in four, and extensive tears have been repaired, not without some damage to the right hand peacock, which lost some of its leg. The paper has a vertical grain, and is discoloured.
It was not exhibited in Whistler's lifetime.
1: [18/25 July 1877], GUW #02599.
2: GUW #02599.