Why did Ghana's independence in 1957 set off a wave across Africa?

Because it proved it could be done. On 6 March 1957 Ghana, formerly the Gold Coast, became the first sub-Saharan African country to gain independence from European colonisation. It was also the first of Britain's African colonies to win majority-rule independence, and the celebrations in Accra were the focus of world attention. Three years later, in 1960, seventeen colonies became independent in a single year, which is why that year is often called the Year of Africa.

The man at the centre was Kwame Nkrumah, who had spent twelve years studying and organising abroad before coming home as an advocate of independence. In 1949 he founded the Convention People's Party, and he picked the word "convention" to carry the masses with us. He called strikes in 1950, was arrested and sentenced to three years in prison, and then won a landslide while still in prison: in the 1951 election, the first universal-franchise general election in colonial Africa, his party took 34 of the 38 contested seats. He was released from prison, and the British governor asked him to form a government.

Ghana's success was not the only cause of what followed. The Second World War had been a catalyst for many independence movements, France's new constitution of 1958 set up a French Community that soon dissolved, and Britain's prime minister Harold Macmillan told South Africa's parliament about "the wind of change blowing through this continent". But Ghana showed it could be done. Of his own later record the picture is mixed: his government grew increasingly authoritarian, and he was overthrown in 1966.