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 these copper deposits could not be exploited commercially until the Southern Rhodesian railway had extended across the Zambezi and continued northward, to reach the Belgian Congo border, which it did in 1909. By that time, mining had started in Katanga, where rich copper oxide ores occurred near the surface. In Northern Rhodesia, the surface ores were of poorer quality, and copper was only worked intermittently at Bwana Mkubwa, until in 1924 rich copper sulphide ores were discovered about 100 feet below the surface. Prior to 1924, there had not been significant exploitation of Northern Rhodesia's mineral resources: there was some