In the Ubangi-Shari Territorial Assembly election in 1957, MESAN captured 347,000 out of the total 356,000 votes and won every legislative seat, which led to Boganda being elected president of the Grand Council of French Equatorial Africa and vice-president of the Ubangi-Shari Government Council. Within a year, he declared the establishment of the Central African Republic and served as the country's first prime minister. MESAN continued to exist, but its role was limited. After Boganda's death in a plane crash on 29 March 1959, his cousin, David Dacko, took control of MESAN. Dacko became the country's first president when the CAR formally received independence from France on 13 August 1960, a date celebrated by the country's Independence Day holiday. Dacko threw out his political rivals, including Abel Goumba, former Prime Minister and leader of Mouvement d'évolution démocratique de l'Afrique centrale (MEDAC), whom he forced into exile in France. With all opposition parties suppressed by November 1962, Dacko declared MESAN as the official party of the state.