1 Samuel Harden Church (1858–1943) grew up in Pittsburgh, and in 1875 went to work as an office boy with the Pennsylvania Railroad Company in that city. He remained with the company for over fifty years, becoming vice-president of the western lines by the time of his retirement in 1928. Church also enjoyed success as a writer. His first novel, Horatio Plodgers: A Story of To-Day, was published in 1878; his numerous later works included a highly praised biography, Oliver Cromwell: A History (1894).

2 In Mark Twain’s Test Book (the only source of this letter text), Cyril Clemens reported that in the late 1890s or early 1900s, Church and Clemens sometimes were dinner guests together at the home of Andrew Carnegie. (Church was secretary of the Carnegie Institute, founded in 1896.) But, according to Cyril, Church’s “contact with Mark really began years before, when he was a young man”: Church could not have read “Personal Habits of the Siamese Twins” in The Celebrated Jumping Frog (1867), because it was not published there. It appeared in Packard’s Monthly for August 1869 (when Church was only eleven), and was then first collected in an American sketchbook, Mark Twain’s Sketches, New and Old, in September 1875 (SLC: 1869; 1875, 208–12). Church could have read the book soon after publication, or sometime within the next few years: The original “Siamese” (conjoined) twins were Chang and Eng, who in 1811 were born in Siam joined at the chest by a band of flesh. They were brought to Boston for exhibition in 1829, and later were exhibited by Barnum, in New York and in Europe. In 1843—having adopted the surname “Bunker”—they married two sisters and settled on adjacent plantations in North Carolina, where they fathered nearly two dozen children. Their deaths in January 1874 caused a flurry of newspaper stories, both factual and fanciful, and may have influenced Clemens to reprint his own 1869 sketch in Sketches, New and Old (Boston Globe: “Chang and Eng,” 23 Jan 74, 1–2; “A New Story of the Siamese Twins,” 29 Jan 74, 3).