The federal system of government in Nigeria was abolished in favour of a unitary one by

The federal system of government in Nigeria was abolished in favour of a unitary one by Major General Johnson Aguiyi-Ironsi. In 1966, a military coup took place in Nigeria which overthrew the civilian government. Major General Johnson Aguiyi-Ironsi, who was the head of the military at the time, became the new leader of Nigeria. As part of his reforms, Major General Johnson Aguiyi-Ironsi abolished the federal system of government that was in place and replaced it with a unitary system. Under the unitary system, power was concentrated at the national level, with the central government having more control over the states and regions. This decision was not well-received by many Nigerians, particularly those in the southern states, who felt that it gave too much power to the central government and undermined the autonomy of the states. However, Major General Johnson Aguiyi-Ironsi's regime was short-lived, as he was overthrown in a counter-coup in July 1966. Subsequent military governments continued with the unitary system until 1979, when a new constitution was adopted that restored the federal system of government.