Factors that necessitated the adoption of a federal system of government in Nigeria:
(i) Minority interest: One of the reasons for the adoption of a federal system is for the protection of the interest of the minority in the country.
(ii) Fear of ethnic domination: There is the fear of one or more majority groups dominating the others.
(iii) Size: Nigeria has a large population, with a wide geographical area.
(iv)To bring government nearer the people: Federalism is adopted in Nigeria to bring the government nearer to the grassroot people. (v) Quick development: It promote quick development in all parts of Nigeria.
(vi) Division of powers: Powers are shared among different tiers of government, making each tier effective in functions allocated to it.
(vii) Employment opportunities: More jobs are created because of the duplication of functions and division of powers.
(viii) Sovereignty of Nigeria: Federalism makes it possible for the formation of strong government, thereby securing the sovereignty ,of Nigeria.
(ix) Autonomy: Preservation of the autonomy of every ethnic groups in the country is made possible through the adoption of federal system of government.
(x)Expansion of markets: The local markets are expanded due to the adoption of a federal system.
(xi) Accommodation: Federalism accommodates the differences- in culture, language, customs, religion, etc., within the system.