Twain's final years
"11 January 1906: note for 267.27," in Autobiography of Mark Twain, Volume 1. 2010
267.27 the New Hampshire hills] Clemens spent the summer of 1906 at Upton Farm, near Dublin, New Hampshire, dictating his autobiography.
From Day By Day for December 7, 1906:
December 7 Friday – Sam was in Washington, D.C., and spoke before the Joint Congressional Committee on Patents in favor of stronger copyright legislation. It was a cause Twain was long chasing. Shelden writes perhaps the most dramatic and telling account of his appearance in his white suit:
On a blustery Friday afternoon in December 1906, Mark Twain arrived for a special appearance at the Library of Congress, trailing smoke from his usual brand of cheap cigar. The temperature hovered at freezing and the skies were gloomy, but he was dressed warmly in a long dark overcoat and a derby from which thick curls of white hair protruded on either side. At the main doors, facing the Capitol, he entered the Great Hall of the Library and made his way down a long marble corridor to the Senate Reading Room, where a hearing was in progress on copyright legislation. The Librarian of Congress—a dapper middle-aged man named Herbert Putnam—was expecting him and emerged from the hearing to escort Twain inside.
All heads turned as the famous guest strode to the front of the chamber, which was full of lobbyists, lawyers, authors, and publishers. Normally used as a private study for senators, the high-ceilinged room had the look and feel of an elegant club…. At a long conference table facing the gathering were the dozen or so members of the Joint Congressional Committee on Patents, chaired by a jowly Republican lawyer from South Dakota, Senator Alfred Beard Kittredge.
…Twain reached his seat and paused to remove his overcoat. By this simple gesture he caused —as one observer later put it—“a perceptible stir.” That was an understatement. Against the fading light of the afternoon Twain emerged as a figure clothed all in white. His outfit perfectly matched his hair, from his white collar and cravat—held in place by a “creamy moonstone”—to his white shoes. Among so many soberly dressed fellows in black and gray, he stood out as a gleaming apparition, impossible to ignore [MTMW xvii-xviii]
Insert: New York World, Dec. 8, 1906, p.1.
William Dean Howells was in the audience. Shelden writes he was “so taken aback by this unconventional outfit that the first words from his mouth were ‘What in the world did he wear that white suit for?’” [ibid.]. Note: wearing white in the dead of winter was considered a shocking breach of etiquette, something Sam often relished doing. However, Twain received extensive press coverage for he flamboyant flaunting of such social norms. A composite of Sam’s speech based on several sources may be found in Fatout, MT Speaking p.533-39.
[I was unable to find an article or image from the referenced newspaper and I don't know who Shelden is.]