If you are researching your family history, census data can be quite valuable to you. If you are trying to trace your roots all the way back to the 1700s, you will need to look at the 1790 census.
However, due to the nature of genealogical research, you should actually start with more recent census data and work backwards. Once you find names, birthdays, birthplaces and other data, you can continue your research to earlier time periods, hopefully as far as the 1790 census.
The 1790 census was the first census required by the US government. According to the US Constitution, a regular census was required to determine both governmental seats and tax collection data. United States marshals and their assistants were required to administer census questions to all residents in their areas.
The census was more than just a list of residents. It was specifically created to determine what the military and industrial capabilities of the country were. To that end, it was organized into several categories. Some of the questions answered by the census included: Head Of Household, Free White Males Over 16, Free White Males Under 16, Free White Females, Slaves and Town Or District Of Residence.
The accuracy of the 1790 census was important to the government. Therefore, marshals were instructed to get everyone in their districts to answer the questions. If anyone refused, they were charged a $20 fine, which was split between the government, the marshals, and their assistants.