The first modern census in the British Isles was taken in order to determine the makeup of the population and its activities. There had been a period of poor harvests and food shortages. A substantial number of agricultural workers had joined the military services and therefore could not be involved with working the land. Like the United States, the British government defined an "as of" date for use by the respondents and this date is reffered to as the "census night." The individual household schedule was to be completed based on the persons who were in the household during the period of Sunday night to Monday morning on the dates listed.

The Census Act of 1800 (41 George III, cap, 15) was enacted and called for a full population enumeration of England, Wales, and Scotland beginning in 1801. The act also called for enumeration to be conducted every ten years thereafter. A census had been performed ever since, with the exception of 1941 when, because of war, very little census work was performed. The population of England and Wales in 1801 was almost nine million, and the population of Scotland was little over 1.6 million. No names were requested, although a few officials did include names in their documents. The questions asked in 1801 included:

• How many inhabited and uninhabited houses are located within the parish, and how many families live in the inhabited houses?
• How many persons are living in the parish, and distinguish males and females of all ages? Military personnell and seamen in military service or on registered vessels were not to be included.
• How many persons are involved with agriculture, with manufacturing or trade, or handicraft, or in other types of employment?
• How many perons' baptisms and burials have been within the parish in 1700, 1710, 1720, 1730, 1740, 1750, 1760, 1770, 1780, and in each subsequent yeare up through 31 December 1800, and distinguish totals by gender. The process of the first census was extensive. Standarized forms were distributed to all households and were to be completed based on persons in a residence as of the census night, 10 March 1801. The information was gathered by enumerators, attached to a copy of the Census Act of 1800. A similar format with similar questions was used in 1811, 1821, and 1831 enumerations.
  
  In 1811, a question was added to determine why a house was unoccupied. In 1821, a question was added to elicit ages of men in order to help determine how many men were able to bear arms. It was also in 1821 that Ireland was first included in the census, and her population at that time was calculated to be over 6.8 million. The 1831 census included more detailed question concerning economic conditions.
  
  

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