In the Kolata book is the interesting tidbit, well, two really, that the previous years (1916, 1917) and two following years (1919, 1920) also had very devasting outbreaks of flu; and that the last really bad flu outbreak of the 19th c was apparently similar genetically to the Spanish Lady, because those old enough to have had that bad outbreak in teh 1890s had immunity to the SL.