Mark Twain and the Quintus Curtius Snodgrass Letters: A Statistical Test of Authorship

Abstract Mark Twain is widely credited with the authorship of 10 letters published in 1861 in the New Orleans Daily Crescent. The adventures described in these letters, which were signed "Quintus Curtius Snodgrass," provide the historical basis of a main part of Twain's presumed role in the Civil War. This study applies an old, though little used statistical test of authorship—a word-length frequency test—to show that Twain almost certainly did not write these 10 letters. The statistical analysis includes a visual comparison of several word-length frequency distributions and applications of the χ2 and two-sample t tests.