Republic in West Africa. Gambia became Britain's first African colony in 1588. In 1902, the inland territory, along the Gambia river, was occupied. In 1965, Gambia became independent, and in 1970, it became a republic. Early in 1982, following a period of political instability, Gambia formed a federation, Sene-Gambia, with Senegal, which, except for a small length of coastline, surrounds it. This union was dissolved in 1989.