Northern Rhodesia had been detained without trial, following claims that they had planned the indiscriminate killing of Europeans and Asians, and of African opponents, the so-called "murder plot". Shortly afterwards, on 12 March 1959, the governor of Northern Rhodesia also declared a State of emergency there, arrested 45 Zambia African National Congress including Kaunda and banned the party. Kaunda later received a 19-month prison sentence for conspiracy, although no credible evidence of conspiracy was produced. The declaration of States of emergency in both Northern Rhodesia and Nyasaland marked the end of attempts by their nationalist parties to work within the colonial system,
Northern Rhodesia African populations being ascertained. After a change in the British government in 1951, the incoming Conservative Colonial Secretary, Oliver Lyttelton removed the condition of sounding out African opinion in November 1951 and pushed ahead against strong African opposition. After further revisions of the proposals for federation, agreement was reached. Following a positive referendum result in Southern Rhodesia, Northern Rhodesia joined the Federation of Rhodesia and Nyasaland when it was created in 1953. In 1946, the Federation of African Welfare Societies was formed, uniting the Welfare Societies that had been set up by educated Africans in towns in the 1930s to