Background to the Conflict
The Barbary States were the present day nations of Algeria, Libya, Morocco, and Tunisia. Except for Morocco, the Ottoman Empire held the states as auxiliary kingdoms, though by the late 18th century they were almost entirely independent from Turkish rule. The North African population was predominantly Muslim, and British and Americans commonly referred to them as "Turks."
Never prosperous traders themselves, the Barbary powers relied on state-sanctioned privateers to patrol the Mediterranean Sea and seize trade ships not protected by international treaties. The Barbary pirates confiscated the cargo and either enslaved the crew and passengers or demanded a steep ransom from their home country. By the time of the American Revolution, the Barbary nations' domination of the Mediterranean Sea had weakened. Though their fearsome privateers still threatened Mediterranean trade, the wealthy nations of Europe (France, Great Britain, and Sweden) purchased protection from piratical raids with expensive tributes. Meanwhile, the ships of nations that could not afford the tributes were in constant danger of Barbary pillaging. In this way, the Barbary threat ensured that England, France, and Sweden dominated Mediterranean trade.
The William Petty, 2nd Earl of Shelburne papers are a wonderful source of information on the state of North Africa in the mid-18th century. Shelburne, who in the 1760s served as first lord of the Board of Trade and secretary of state, received intelligence reports on the commercial and military capabilities of the North African nations. The bulk of this material is in the Shelburne papers, Volumes 19, 40, and 111.
Volume 19 is "An Account of the Military and Naval Power of the Tripoly, Tunis, Algiers & Morocco, & of the Produce & Trade of those Piratical States &c. &c." These 1765 reports contain brief histories on each state, along with details on their populations, trade capabilities (imports and exports), the condition and size of their militaries and navies, geographical advantages and disadvantages, governmental systems, and diplomatic alliances. The reports also lay out potential British blockade strategies.
Volume 40 contains "Correspondence with English consuls and agents to the Barbary States, letters to the Algerian Dey, Barbary treaties; and letters concerning Mediterranean Passes," (1766-1768).
Volume 111 of the Shelburne papers is a report on the "General State of the Trade of Algiers," which lists British exports and imports to Algiers, Morocco, Tunis, and Tripoli, and "Trade carried by the Tripoline Moors to the Inland Parts of Africa, 1766."
The following documents are in Volume 40. The left image links to two sections of an agreement with Morocco allowing British merchants to sail in the Mediterranean (1766). The right image links to a letter from the Emperor of Morocco to King George III:
The Clements Library's Charles Townshend papers hold additional material documenting British dealings with the Barbary States. These papers include details of Augustus Kepple's (1725-1786) tribute negotiations with Algiers, Tripoli, and Tunis in 1750-1751 (see Box 297-1), along with a printed pamphlet entitled "The Case of the Merchants who have Suffered by the Seizure of the Treasure on board the Prince Frederich Packet-Boat by the Algerines" (see Box 8-30).