In the last half of the 19th century, yellow fever plagued the American South. It stalked the region’s steaming cities, killing its victims with overwhelming hepatitis and haemorrhage. Margaret Humphreys explores the ways in which this tropical disease hampered commerce, frustrated the scientific community, and eventually galvanized local and federal authorities into forming public health boards. She pays particular attention to the various theories for containing the disease and the constant tension between state and federal officials over how public funds should be spent. Her research recovers the specific concerns of the late 19th- and early 20th-century South, seeking to broaden the reader’s understanding of the evolution of preventative medicine in the USA.