following the april 1974 revolution in portugal, the paigc became an active political movement in cape verde. in december 1974, the paigc and portugal signed an agreement providing for a transitional government composed of portuguese and cape verdeans. on 30 june 1975, cape verdeans elected a national assembly which received the instruments of independence from portugal on 5 july 1975. in the late 1970s and 1980s, most african countries prohibited south african airways from overflights but cape verde allowed them and became a centre of activity for the airline's flights to europe and the united states.