The earliest evidence of civilization in this region are mysterious circles of huge stone columns (megaliths) in the vicinity of the Gambia and Saloum rivers. The inhabitants of modern Senegal and The Gambia are descendants of Negroid peoples who settled some 1,400 years ago From 1445 Portuguese mariners traded with the Wolof and Serer kingdoms but in 1588 they were driven out by the Dutch. Ultimately the French gained dominance from their settlement on St. Louis Island in the estuary of the Senegal, capturing Rufisque and Gorée Island, which served as slave trading posts until the abolition of this trade in the first half of the 19th Century. Millions of Africans were shipped from Gorée to the New World during the 1700s. Eventually these coastal centers and Dakar became integral parts of France, electing their own deputies to the National Assembly. France not onlyannexed Senegal, but used the colony as a base for further expansion eastward. A Catholic poetpolitician, Léopold Sedar Senghor, led Senegal to independence in 1960 and exercised virtual one-man rule until his voluntary retirement in 1981 when he stepped down in favor of his prime minister, Abdou Diouf. During his term as president, Diouf witnessed the creation in 1982 together with The Gambia of the Confederation of Senegambia and its breakup in 1989. In the presidential election of March 2000, Diouf, as leader of the Parti Socialiste du Sénégal or Socialist Party of Senegal (PSS), was defeated at the polls and succeeded as president by Abdoulaye Wade, representing the Parti Démocratique Sénégalais or Senegalese Democratic Party (PDS). Wade inherited an ongoing problem posed by the secessionist Mouvement des forces democratiques de Casamance (MFDC), led by the Rev. Augustin Diamacoune in southern Senegal.