1 page, 12mo, bifolium, on 21 Fifth Ave stationery, some very slight toning to edges and corners.  An invitation: "The next Doe-Luncheon will happen at the above address on Tuesday, Feb. 11 at 1p.m. please don't fail to come." 

After several years of living in New York, Twain was well-known for entertaining his male friends at stag luncheons. In 1908, his friend, writer Kate Douglas Wiggin, chastised him for only hosting his male friends. She "argued that 'brilliance is not limited to the stags--give a doe-luncheon & you will see.' 'And she was right,' Clemens conceded. The first 'doe-luncheon' on 14 January 1908 was a great success. 'I was the only lady of my sex present,' Clemens reported modestly" (see "Mark Twain at Play," The Bancroft Library, 2010). Twain organized a second doe-lunch for 11 February 1908, and in addition to Riggs, other attendees included a young Ethel Barrymore, and Frances Hodgson Burnett.