The famous 1918 "Spanish" influenza pandemic killed over 500,000 people in the United States and over 40 million people worldwide. My findings show that the pandemic mortality was selective, and the population left in its wake was healthier than before the pandemic. The axis of selection was tuberculosis. Tuberculosis death rates plummeted in the years after 1918. Confirmatory morbidity/mortality patterns are found using microdata from the Union Army data set. The 1918 pandemic is at the center of current concerns about catastrophic influenza, and these results show that countries with high TB prevalence today may be hit hardest by the next pandemic.