Census was first, conducted in the area known today as Nigeria in the year 1866 by the British colonial government within the Colony of Lagos. There were also decennial censuses conducted only for Lagos Colony in the years 1871, 1881 and 1901 respectively. Ten years after in the year 1911, the census exercise covered the Southern Protectorate including Lagos and the Northern Protectorate.
The 1911 census-taking had a wider coverage as it involved the whole of Southern Nigeria. This was possible because in 1906, five years before the census, Lord Fredrick Lugard who was the Governor-General of Nigeria merged the Lagos colony with the Southern Nigeria protectorate.
The amalgamation of the Southern and Northern Nigeria Protectorates in 1914 by Lord Lugard and the enactment of a Census Ordinance in 1917 brought remarkable changes to the conduct of censuses in Nigeria as it paved the way for the conduct of the first nationwide census in 1921 under Sir Hugh Clifford the then Governor-General of Nigeria.
The enumeration was divided into two parts. The first part known as the Township census, counted the residents of the towns and cities, while the second part was the Provincial census which covered the whole country. The township census was conducted within one day and gave accurate results, particularly in comparison with the provincial censuses. The provincial census took more than two months and it was based on tax records of the residents. It suffered from inadequate staffing and the public boycotted it because they felt it would lead to higher taxes. In Southern Nigeria, the preliminary figures were adjusted upwards before the result of 8.4 million was published. The published figure for Northern Nigeria was 10.4 million.
The 1931 census which was the second nationwide census was not comprehensive in its coverage because only six towns including Lagos and 201 villages spread across the country were enumerated. Estimates from existing tax records were put to use in compiling the figures of other places.
The 1931 census was affected by the world economic depression and the numerous tax riots in Calabar and Owerri provinces in the then Eastern region prevented enumeration in the major towns of these areas in 1931 while the locust invasion resulted in the diversion of some census staff to perform locust duties in some parts of the Northern provinces.
In 1941, the census did not take place because of the Second World War. The census exercise resumed with the conduct of the 1951/53 census after the Second World War. The 1951/53 census was conducted under the leadership of Sir John Macpherson the Governor-General. The census was staggered. Enumeration was carried out separately in four parts of the country, i.e Lagos colony, Northern Region, Western, Mid-western Region and the Eastern region respectively. The census in Northern Nigeria was conducted between May and July, 1952 while it was conducted in the West and Mid-West in December 1952 and January 1953. In the Eastern part of the country, the census was conducted from May to August 1953. The lack of universality of the census taking made it difficult to aggregate the census data nationally. This census was the last to be conducted by the British colonial government and was described as the first modern, national and well-planned headcount in Nigeria. It was conducted over a period of three years and was described as the longest census in the history of the country.
In 1941, the census did not take place because of the Second World War. The census exercise resumed with the conduct of the 1951/53 census after the Second World War. The 1951/53 census was conducted under the leadership of Sir John Macpherson the Governor-General. The census was staggered. Enumeration was carried out separately in four parts of the country, i.e Lagos colony, Northern Region, Western, Mid-western Region and the Eastern region respectively. The census in Northern Nigeria was conducted between May and July, 1952 while it was conducted in the West and Mid-West in December 1952 and January 1953. In the Eastern part of the country, the census was conducted from May to August 1953. The lack of universality of the census taking made it difficult to aggregate the census data nationally. This census was the last to be conducted by the British colonial government and was described as the first modern, national and well-planned headcount in Nigeria. It was conducted over a period of three years and was described as the longest census in the history of the country.
The 1962 census was the second countrywide headcount in Nigeria and the first since independence in 1960. It was better organized and more comprehensive when compared to the 1952/53 census. However, the results of the census exercise were canceled after a heated and prolonged controversy over the inflation of figures in some regions. According to the 1962 census, preliminary figures released by the Census Board, the population of Nigeria was 45.26 million with Northern Nigeria having 22.01 figure and the other three regions having a combined figure of 23.25 million. Southern politicians applauded the result but it was outrightly rejected by Northern politicians. The then Prime Minister Sir Abubakar Tafawa Balewa in consultation with the Regional Premiers announced the cancellation of the census results and two weeks later constituted a five-member Board to conduct the 1963 census.
The 1963 census exercise despite the controversies it generated especially its rejection by Governors of Eastern and Midwestern Nigeria who went to the Supreme Court to contest the results but lost was accepted by the Federal Government. The population figures derived from the 1963 census subsisted as a base for development planning and resource allocation until the next attempt in 1973.
The 1973 census was conducted from November 25 to December 2, 1973 and it was adjudged technically sound. This was largely because it was the first time an enumeration area demarcation was carried out before the actual census and it was also the first-time homeless people were taken into account and the census became more detailed at last. The result of the exercise was however not published and the entire exercise was canceled after the announcement of a population figure of 79.76 million population by General Yakubu Gowon the then Military Head of State. The cancellation was based on the fact that, like the two censuses before it, there were allegations of organized inflation across the States in the country and aside from the over-inflation of the population figures by states, other reasons advanced as being responsible for the problems encountered by the 1973 census exercise include but not limited to; 1. The size and composition of the membership of the National Census Board 2. Interference in the work of the Census Board by the Federal Military Government 3. The appointment of two State Governors to serve on the Committee of experts of the Board. With the cancellation of the results, the Board was dissolved in 1975.
The National Population Commission was constituted in 1988. The Commission made elaborate preparations for the census exercise which was conducted between 29th and 31st October, 1991. The result of the census was released in 1992 with a population figure of 88.5 million.
President Olusegun Obasanjo in November 2001 inaugurated the National Population Commission with the mandate of conducting an accurate, reliable and credible census for the country. In pursuance of a reliable and credible census, the Commission designed its methodology and incorporated new techniques and technology for the conduct of the census. Thus, for the first time, the 2006 census employed the use of Geographical Positioning System (GPS) and Satellite Imagery to carve out Geo-referenced Enumeration Area maps, OMR/ICR/OCR machine-readable forms to record information, Automated Fingerprint Identification System (AFIS) to read fingerprints so as to detect multiple counting. President Obasanjo presented to Nigerians the provisional population and housing result of 140,003,542 million people in March 2006.