The amalgamation of the three areas that existed separately between 1861 and 1913 to form Nigeria was due to some reasons.
INCREASED REVENUE IN THE SOUTH
Between 1900 and 1913, there was a steady increase in the revenue of the southern protectorate while British treasury continued to give subsidy to the northern protectorate.
The southern protectorate got much revenue from the sale of palm produce, cocoa and rubber while the northern protectorate had no visible source of revenue.
As a result of this, the imperial government in Britain sent regular grants of £300,000 yearly to the Northern protectorate. This implied that tax payers’ money in Britain was being used in running a colonial territory.
This act was criticized by British citizens. The British colonial office in London, therefore, advised the colonial government in Nigeria to use the revenue derived from the southern protectorate to balance the ailing economy of the northern protectorate.
Another economic reason was the desire to establish a transportation policy for the two protectorates. The northern protectorate was land-lock while the southern protectorate had links with the Atlantic Ocean.
The colonial government felt that the rich southern protectorate could assist the northern protectorate until the later became self-supporting. The northern protectorate was then linked to the southern protectorate through road and railway systems.
THE NEED TO CONCENTRATE EFFECTIVE POWER AT THE CENTRE
Before the amalgamation exercise, governmental powers were shared among the administrative areas namely the protectorates and the colony of Lagos. There was no effective co-ordination among these bodies.
The imperial government decided to concentrate all governmental powers on the Governor. This was done based on two reasons.
First, the imperial government wanted to have effective control of all her colonies as this would minimize the cost of personnel and administration.
Second, the imperial government wanted to form a political union of the colony of Lagos, the southern and northern protectorates.
OUTLET TO THE SEA
The northern protectorate was land locked and had no assess to the sea. This created transportation problem. Goods and people could not be easily transported to the Atlantic Ocean. The colonial government had to spend a lot of money to get people and goods transported from the north to the south.
NEED FOR EFFECTIVE CONTROL
Both the northern and southern protectorates were owned by the British but governed differently. In view of this, the colonial government in London wanted to have full control of the political and economic affairs of the whole colony of Nigeria.
The government wanted the activities of the two protectorates centralized under one authority. This would make for the effective and uniform administration of the colony.