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 cattle farming in Barotseland, but Northern Rhodesia had attracted little white settlement, in contrast to its southern neighbour. Unlike Southern Rhodesia, which had seen a flood of fortune-seeking prospectors seeking to set up independent mines, Northern Rhodesia's mining policy was to agree large-scale deals with major commercial mining companies. Large-scale mining on the Northern Rhodesian Copperbelt started after 1924 and was mainly financed from the United States of America and South Africa. Chester Beatty's and Sir Edmund Davis's Selection Trust already had an interest in the fairly small Bwana Mkubwa copper mine, which had opened in 1901 on the site