Gaboon (called also the Mpongo or Mpongwe in the language of the people at its mouth), a bay on the coast of west Africa, about lat. 0° 30' N, Ion. 9° 20' E. It receives the united stream of the Olombo and the Rhamboe, and was formerly believed to be a large and powerful river; but it is simply an inlet of the Atlantic ocean, about 40 m. long, 9 m. wide, and from 10 to 60 ft. deep. In 1843 the French established a fortified factory on the coast of the Gaboon bay, and obtained gradually from the native chiefs the whole coast land from Cape Lopez, in lat. 0° 36' S., to the Laucie promontory, in lat. 0° 40' N In 1867 the area of this colony was reported to be 8,000 sq. m. It had about 5,000 inhabitants and 1,000 troops. The latter were withdrawn during the Franco-German war of 1870-71; and the protectorate of Grand Bassam and Assinie was abandoned by the French in 1872, because they could not control the native chiefs. At the beginning of 1874 there were no French authorities at Gaboon except the naval officers at the station, whose commander acts as governor. The settlement has substantial public buildings, stores, hospitals, a small dockyard, and a large depot of coals. French, English, American, German, and Portuguese missionaries reside here, as well as a French bishop.

The Mpongwe language, which is spoken by the natives, has been reduced to writing, and is taught grammatically in the American missionary schools, and the French have translated part of the New Testament into it. The use of a corrupt English jargon is spreading. A number of slaves continue to be kept all along the coast for domestic purposes.With a view of making the colony self-sustaining, an export duty has been recently imposed by the home government, which hampers trade.