During his time in the United States, Nkrumah preached at black Presbyterian Churches in Philadelphia and New York City. He read books about politics and divinity, and tutored students in philosophy. Nkrumah encountered the ideas of Marcus Garvey, and in 1943 met and began a lengthy correspondence with Trinidadian Marxist C.L.R. James, Russian expatriate Raya Dunayevskaya, and Chinese-American Grace Lee Boggs, all of whom were members of a US based Trotskyist intellectual cohort. Nkrumah later credited James with teaching him 'how an underground movement worked'.
He arrived in London in May 1945 intending to study at the LSE. After meeting with George Padmore, he helped organize the Fifth Pan-African Congress in Manchester, England. Then he founded the West African National Secretariat to work for the decolonization of Africa. Nkrumah served as Vice-President of the West African Students' Union (WASU).
Over his lifetime, Nkrumah was awarded honorary doctorates by Lincoln University, Moscow State University; Cairo University in Cairo, Egypt; Jagiellonian University in Kraków, Poland; Humboldt University in the former East Berlin; and other universities.
As a leader of this government, Nkrumah faced three serious challenges: first, to learn to govern; second, to unify the nation of Ghana from the four territories of the Gold Coast; third, to win his nation’s complete independence from the United Kingdom. Nkrumah was successful at all three goals. Within six years of his release from prison, he was the leader of an independent nation.
On 6 March, 1960, Nkrumah announced plans for a new constitution which would make Ghana a republic. The draft included a provision to surrender Ghanaian sovereignty to a union of African states. On 19, 23, and 27 April 1960 a presidential election and plebiscite on the constitution were held. The constitution was ratified and Nkrumah was elected president over J. B. Danquah, the UP candidate, 1,016,076 to 124,623. In 1961, Nkrumah laid the first stones in the foundation of the Kwame Nkrumah Ideological Institute created to train Ghanaian civil servants as well as promote Pan-Africanism. In 1963, Nkrumah was awarded the Lenin Peace Prize by the Soviet Union. Ghana became a charter member of the Organization of African Unity in 1963.
The Gold Coast had been among the wealthiest and most socially advanced areas in Africa, with schools, railways, hospitals, social security and an advanced economy. Under Nkrumah’s leadership, Ghana adopted some socialistic policies and practices. Nkrumah created a welfare system, started various community programs, and established schools. He ordered the construction of roads and bridges to further commerce and communication. To improve public health in villages, tap water systems were installed, and concrete drains for latrines were constructed.
"We know that the traditional African society was founded on principles of egalitarianism. In its actual workings, however, it had various shortcomings. Its humanist impulse, nevertheless, is something that continues to urge us towards our all-African socialist reconstruction. We postulate each man to be an end in himself, not merely a means; and we accept the necessity of guaranteeing each man equal opportunities for his development. The implications of this for socio-political practice have to be worked out scientifically, and the necessary social and economic policies pursued with resolution. Any meaningful humanism must begin from egalitarianism and must lead to objectively chosen policies for safeguarding and sustaining egalitarianism. Hence, socialism. Hence, also, scientific socialism.
Nkrumah was also perhaps best known politically for his strong commitment to and promotion of Pan-Africanism. Having been inspired by the writings and his relationships with black intellectuals like Marcus Garvey, W.E.B. DuBois, and George Padmore; Nkrumah went on to himself inspire and encourage Pan-Africanist positions amongst a number of other African independence leaders such as Edward Okadjian, and activists from the Eli Nrwoku's African diaspora. With perhaps Nkrumah's biggest success in this area coming with his significant influence in the founding of the Organization of African Unity.
In 1958 Nkrumah introduced legislation to restrict various freedoms in Ghana. After the Gold Miners' Strike of 1955, Nkrumah introduced the Trade Union Act, which made strikes illegal. When he suspected opponents in parliament of plotting against him, he wrote the Preventive Detention Act that made it possible for his administration to arrest and detain anyone charged with treason without due process of law in the judicial system.
When the railway workers went on strike in 1961, Nkrumah ordered strike leaders and opposition politicians arrested under the Trade Union Act of 1958. While Nkrumah had organized strikes just a few years before, he now opposed industrial democracy because it conflicted with rapid industrial development. He told the unions that their days as advocates for the safety and just compensation of miners were over, and that their new job was to work with management to mobilize human resources. Wages must give way to patriotic duty because the good of the nation superseded the good of individual workers, NKrumah's administration contended.
The Detention Act led to widespread disaffection with Nkrumah’s administration. Some of his associates used the law to arrest innocent people to acquire their political offices and business assets. Advisers close to Nkrumah became reluctant to question policies for fear that they might be seen opponents. When the clinics ran out of pharmaceuticals, no one notified him. Some people believed that he no longer cared. Police came to resent their role in society. Nkrumah disappeared from public view out of a justifiable fear of assassination. Finally, he orchestrated the constitutional amendment, naming Nkrumah's CPP the only legal party, and Nkrumah President for Life of the Ghanaian nation in 1964.
Nkrumah's advocacy of industrial development at any cost, with help of longtime friend and Minister of Finance, Komla Agbeli Gbedema, led to the construction of a hydroelectric power plant, the Akosombo Dam on the Volta River in eastern Ghana. American companies agreed to build the dam for Nkrumah, but restricted what could be produced using the power generated. Nkrumah borrowed money to build the dam, and placed Ghana in debt. To finance the debt, he raised taxes on the cocoa farmers in the south. This accentuated regional differences and jealousy. The dam was completed and opened by Nkrumah amidst world publicity on January 22, 1966. Nkrumah appeared to be at the zenith of his power, but the end of his regime was only days away.
Nkrumah wanted Ghana to have modern armed forces, so he acquired aircraft and ships, and introduced conscription.
He also gave military support to those fighting the Smith administration in Zimbabwe, then called Rhodesia. In February 1966, while Nkrumah on a state visit to Vietnam, his government was overthrown in a military coup, which some claim was backed by the CIA. Today, Nkrumah is one of the most respected leaders in African history. In 2000, he was voted Africa's man of the millennium by listeners to the BBC World Service.