In epidemiological terms, an epidemic is an unusual occurrence of a disease in an area the size of a city, state, or affecting a part of a country. A pandemic is an epidemic which covers more than a local, state, or national area generally involving two or more continents and sometimes almost the entire world. Hence, this book might better have been entitled, The Great Pandemic. Pandemics were relatively infrequent in the last half of the 19th Century, and none occurred in the 20th until influenza appeared in 1918-1919, taking over 500,000 lives in the United States and an estimated 20 million in the world.
The author uses news items, editorials and articles from newspapers, and personal interviews as source material. The account of the epidemic is written in a popular way and includes pronouncements by administrative and health officials, quacks, citizens, and others, throughout interspersed with the recording of