The curtain fell on piracy's golden age in the 1720s. But it rose again fifty-five years later when American revolutionaries fought England for their freedom. The Revolutionary War was fought at sea by sailors and privateers. The tiny American navy had only thirty-four ships. But more than four hundred privateers attacked British merchants, crippling trade. As in centuries before, those who lost ships to privateers called them pirates. But to Americans fighting for their rights, the privateers were heroes. When the United States later fought England in the War of 1812, naval privateers once again lashed out at British shipping.

By the mid-1800s, technology helped put an end to piracy. The navies of Britain and the United States had steam-powered ships that could sail anywhere, even on windless days. Pirates could not afford expensive...