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 crashed in 1931. An international agreement restricted output. This caused a catastrophe in Northern Rhodesia where many employees were sacked, and put an end to hopes which many Europeans had held of turning Northern Rhodesia into another white dominion like Southern Rhodesia. Many settlers took this opportunity to move back to Southern Rhodesia, while Africans returned to their farms. Despite the economic crash large firms were still able to maintain a profit. The fact that unemployed workers had left meant there were no increases in taxation, and labour costs remained low. At a 1932 conference of copper producers in New