Cod, Massachusetts and nearby cities. Whale oil was in demand chiefly for lamps. By the 18th century whaling in Nantucket had become a highly lucrative deep-sea industry, with voyages extending for years at a time and traveling as far as South Pacific waters. During the American Revolution, the British navy targeted American whaling ships as legitimate prizes. In turn, many whalers fitted out as privateers against the British. Whaling recovered after the war ended in 1783 and the industry began to prosper, using bases at Nantucket and then New Bedford. Whalers took greater economic risks in search of profit, expanding their hunting grounds. Investment and financing arrangements allowed managers of whaling ventures to share their risks by selling some equity, but retain a substantial portion of the profit. As a result, they had little incentive to plan their voyages to minimize risk. Ten thousand seamen manned the ships, including more than 3,000 African American seamen. Early whaling efforts concentrated on right whales and humpbacks, which were found near the American coast. As these populations declined and the market for whale products grew, American whalers began hunting sperm whales. The sperm whale was particularly prized for spermaceti, a dense waxy substance that burns with an exceedingly bright flame that is found in the spermaceti organ, located forward and above the skull. Hunting sperm required longer whaling voyages. Whale oil was essential for illuminating homes and businesses in the 19th century, and lubricated the machines of the Industrial Revolution. Baleen (the long keratin strips that hang from the top of whales' mouths) was used by manufacturers in the United States and Europe to make varied consumer goods. British competition and import duties drove New England whaling ships out of the North Atlantic and into the southern oceans, ultimately making whaling into a global economic enterprise. The mid 19th century was the golden age of American whaling. From the Civil War, when Confederate raiders targeted American whalers, through the early 20th century, the American whaling industry suffered economic competition, especially from kerosene, a superior fuel for lighting. Localities A number of New England towns were heavily involved in whaling, particularly Nantucket and New Bedford. Nantucket began whaling in 1690 after recruiting a whaling instructor, Ichabod Paddock. The south side of the island was divided into three and a half mile sections, each with a mast erected to look for the spouts of right