Why it's the capital
The Portuguese founded Bissau as a trading post in 1687. In 1941 the capital of Portuguese Guinea moved here from Bolama, and when Portugal granted independence, Bissau became the capital of the new state.
Capital of Guinea-BissauBissau is on the wide estuary of the Geba River, just in from the Atlantic Ocean, and the land around it is very low-lying. Ocean-going ships can sail up the river for about 80 km beyond the city.
The Portuguese founded Bissau as a trading post in 1687. In 1941 the capital of Portuguese Guinea moved here from Bolama, and when Portugal granted independence, Bissau became the capital of the new state.
On the West African coast, Bissau sits roughly halfway between Dakar to the north and Conakry to the south, at a wide river mouth.
Guinea-Bissau and its neighbour Guinea are different countries. Bissau is the capital of Guinea-Bissau, while Guinea's capital is Conakry.
Sources: Wikipedia: Bissau, Wikipedia: Amílcar Cabral