Extraordinary rendition--the practice of abducting criminal suspects in locations around the world--has been criticized as an unprecedented expansion of U.S. police powers. But America's aggressive pursuit of fugitives beyond its borders far predates the global war on terror. Uncle Sam's Policemen investigates the history of international manhunts, arguing that the extension of U.S. law enforcement into foreign jurisdictions at the turn of the twentieth century forms an important chapter in the story of American empire.

In the late 1800s, expanding networks of railroads and...