U.S. vs. the pirates

In 1801, the Barbary Pirates declared war on the U.S. We had been paying them tribute since 1784, but Thomas Jefferson (then ambassador to France) eventually argued successfully that paying further tribute would only encourage more attacks. By 1800, the US was paying nearly 20% of its annual revenues in ransom and tribute to privateering states. When Jefferson was elected President, he sent a group of frigates to the Mediterranean to provoke the Pasha of Tripoli (sometime leader of the Barbary states). The Pasha backed down immediately, but other Barbary leaders did not, and war ensued. Hostilities did not end until 1805.