Census of 1790 - The Constitution
The Constitution of the United States, Article I, Section 2, Clause 3 states that "The marshals of the several districts of the United States shall be, and they are hereby authorized and required to cause the number of the inhabitants within their respective districts to be taken..." Article 1, Section 9, Clause 4 of the Constitution stated "No Tax shall be laid, unless in Proportion to the Census".

The Census of 1790 - 1790 Census Act for kids
The 1790 Census Act was passed on March 1, 1790. The law as detailed in the 1790 Census Act required that every household be visited and that completed census schedules be posted in "two of the most public places within [each jurisdiction], there to remain for the inspection of all concerned" and that "the aggregate amount of each description of persons" for every district be transmitted to the President.

Reason for the First Census of 1790
The Constitution provided that representatives should be distributed among the states according to population (as modified by the federal ratio). To do this it was necessary to find out how many people there were in each state.

• Federal Ratio: It had been agreed that slaves should be counted at three-fifths of their real number. This rule was called the "federal ratio." The result of this rule was to give the Southern slave states representation in Congress out of all proportion to their voting population

• The 1790 Census was the first law that had an impact on Congressional apportionment. As a result of the 1790 Census, the House of Representatives increased from 69 members, in the 2nd US Congress, to 105 members in the 3rd Congress.

The Census was also used to assess the industrial and military potential of the country.

US Census of 1790 for kids - Where was the Census Taken?
Marshals took the population count in the original 13 States, plus the districts of Maine, Kentucky and Vermont, and the Southwest Territory (Tennessee).

US Census of 1790 for kids - What were the requirements of the Census?
The Marshals were directed to detail the name of the head of the family and the number of people in each household of the following categories and descriptions:

• Free White males of 16 years and over

• Free White males under 16 years

• Free White females

• All other free persons

• Slaves

The Census of 1790 for kids - The First Census
The Census of 1790 in the United States of America recorded the population on August 2, 1790. In the First count the population of the USA was enumerated (counted) as 3,929,214 people.

US Census of 1790 for kids - Slaves
There were then nearly 700,000 slaves in the country. Of these only 50,000 were in the states north of Maryland. The country was therefore already divided into two sections. One section where slavery was of little importance and  the other section where slavery was of great importance.