SENEGAMBIA is a term adopted by geographers to indicates part of the western coast of Northern Africa, but it has not always been applied to the same extent of country. Originally it was only used to indicate the countries which lie between the Senegal and Gambia, from the names of which two rivers the term has been composed, or rather, only the tract between the European establishments on the banks of these rivers, for tho country itself was almost entirely unknown in Europe nearly to the end of the last century. It is true that this part of the African coast was visited by Hanno, the Cartha ginian admiral, and that it was again discovered by the Portuguese in the 16th century, between 1144 and 1469. (Ames, vol cols. 105, 107.] The Portuguese also formed several commercial establishments near tho mouths of the principal rivers, but they were neglected after the route to the East Indies had been discovered by Vasco de Gams (1497). The French and the English next tried to get a footing there, and the French acquired the Senegal about 1675, and the English the Gambia in 1686. They formed settlements at the mouths of these rivers, and their merchants began to trade on the banks, forming depots for their goods at certain places. The remotest French com mercial establishment was at St. Joseph, or Makannah, not very far below the Feloo Falls, and the English advanced by degrees to Baraconda, some miles below the last rapids of the Gambia. In the year 1788, an association was formed in London for promoting the discovery of the interior parts of Africa. The year before, the settlement of Sierra Leone had been made for the negro slaves who had obtained their freedom in the West Indies. Since that period the interior of Western Africa has been explored by several travellers, among whom may be named Houghton in 1790-91, Winterbottom in 1794, and Mungo Park in 1795-97 and in 1805. After the peace of 1814, the British government sent out an expedition for the purpose of opening a trade between the countries on the Joliba and the settle ments on the Gambia. Though this expedition did not accomplish its object, it traversed a great part of Senegambia in different directions (between 1817 and 1820), and collected much interesting information. Denham and Clapperton succeeded in penetrating from Tripoli, through the Great Desert, to Borneo in Sddan, whence they advanced as far westward as Sackatu (near E. long.).
Before these journeys were accomplished, Laing set out (1822) from Sierra Leone, and reached the town of Timbo. The French also commenced to explore these countries. Mollien, departing (1818) from St. Louis, traversed the whole country betweeu the mouth of the river Senegal and the sources of the Gambia, crossing the routes of the British travellers. He went as far as Timbo. Caillid, in his great journey, traversed the country between the river Nuilez and Sierra Leone in 1827, and after having passed the Ba Fing, or Senegal, not far from its source, reached Timbuctoo, and returned to Europe by the Great Desert, and through the empire of Marocco.
By these numerous journeys, a tolerably exact notion has been obtained of the natural features and productive powers of the countries of Western Africa which are drained by the rivers whose mouths are found between the embouchure of the Senegal (16° 30' N. lat.) and the island of Sherboro (7° 30' N. lat.). These countries may be regarded as separated into two unequal parts, the northern and larger of which may be called Senegambia, and the southern and smaller part Sierra Leone. The dividing-line between these two countries begins at Cape Verge, whence it extends in an east-north east direction to the sources of the river Nuiez, and thence eastward to those of the rivers Rio Grande and Gambia. Towards the east Senegambia is supposed to comprehend all the countries drained by the numerous upper branches of the Senegal, and to extend to the high land which separates them from the countries on the banks of the Upper Joliba. A continuous ridge of high land extends along the northern side, and close to the banks of the Ba 'Woolima, or eastern branch of the Senegal, from its source to its junction with the Ba nog, or western branch ; and this ridge constitutes the north eastern boundary of Senegambia. Farther west the valley of the river Senegal, which is bordered on the north by the great desert of the Sahara, is considered to be the most northern country belonging to Senegambia. The Atlantic Ocean washes its western shores, con stituting a coast-line which probably exceeds a thousand miles in length. The countries inclosed within these boundaries cover an area exceeding 200,000 square miles.