'The English System' is a history of port health and immigration at a critical moment of transformation at the end of the 19th and beginning of the 20th century. During the later 19th century, British public health officials transformed the medieval quarantine system into a novel 'English System' of surveillance to control the introduction of infectious disease. This book explores the tensions and transition in the regulation of port health from a paradigm focused on the origin of disease to one which converged on the origin of the diseased