In the six years that elapsed between the first General Elections in 1951 and Ghana's attainment of independence in 1957, the government of the CPP took bold initiatives to advance the development of the country economically, socially and politically. In the economic sphere, it launched a 5-year Development Plan for the country. Its achievements included the sealing of many of the country’s existing roads and the construction of new ones; the construction of a bridge over the Volta at Adomi, to facilitate travel between what is now the Volta Region and the rest of the country; the construction of a new and modern harbour at Tema; the extension of Huni valley to kade railway line to Accra and tema; support for the cocoa industry and formulation of plans for the building of a hydro-electricity plant at Akosombo. In the social field, the CPP Government launched, in 1952, the free compulsory primary education programme for children aged between 6 and 12 years. It increased Government expenditure on primary education from £207,500 in 1950-51 to over £900,000 in 1952. As a result, the number of registered pupils in elementary schools increased from 212,000 in 1950 to 270,000 in 1952. Sixteen new Teacher Training Colleges were established to increase the output of teachers while the number of Government-assisted Secondary Schools increased from 13 in 1951 to 31 in 1955. In 1952 the CPP Government established the Kumasi College of Arts Science and Technology and co-operated with Nigeria, the Gambia and Sierra Leone to establish the West African Examinations Council to organize and administer examinations in the four countries. University education was free and textbooks were supplied to all pupils in primary, middles and secondary schools. Politically, the CPP Government accelerated the pace of Africanisation of the civil and public service, resulting in the rise in the number of Africans in the so-called “European posts” from 171 in 1949 to 916 in 1954 and to 3,000 in 1957. It also introduced a new system of Local Government with an elected majority in 1952. But the biggest political challenge to the Government during the period was the threat to the cohesion of the state.