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 mining was booming. When Northern Rhodesia became a Protectorate under the British Empire on 1 April 1924, a Legislative Council was established on which the Governor of Northern Rhodesia sat "ex officio" as Presiding Officer. The initial council consisted entirely of nominated members, as no procedure existed at the time for holding elections. However, the members were divided between the "official members" who held executive posts in the administration of the Protectorate, and the "unofficial members" who held no posts. In 1926, a system of election was worked out and the first election was held for five elected unofficial members,