Census 1790 - 1930:
Form used: Long Form
The U.S. Constitution directs that an accurate and complete count of the population must be taken every 10 years. The first census count was taken in 1790 when George Washington was president and Thomas Jefferson as Secretary of State led the census endeavor. The first census was taken in the original 13 states and the territories of Kentucky, Maine, and Vermont, and Tennessee. The census totals are used to apportion seats in the U.S. House of Representatives.
The first census was written on whatever the collection marshals could find and use for information collection. There were specific questions but sometimes the marshals added their own questions. The next two censuses saw the states creating schedules each distinct in format. In 1830 a standardized schedule was created for use across the country and it's territories. Early census forms only asked a few questions. In 1790 there were only 6 questions that appear on the census questionnaire; by 1930 there were 34 questions.
Form used: Short Form, Long Form
Beginning in 1940 additional demographic questions were added to get more in depth information about housing; in particular, looking at persons abroad, in dormitory style housing, and those in the military. These changes led to the use of two different census forms; the short and the long. All households received the short forms and certain percentages of the population received the long form.
Another major change to the census process came in 1960 when the first mail out forms were sent to each household. Over these 70 years the use of computers to process the enumeration data expanded and made analysis more robust. To ensure greater accuracy the block level geography was added in the 1970 census.
2010 - present:
Form used: Short form
In 2010 there was only one questionnaire and it had only 10 questions. The American Community Survey was begun to collect data about education, housing, jobs, etc. The ACS collects data every year and provides a statistical application where the Decennical Census provides a complete count. Questions for the census must be submitted at 3 years in advance of Census Day. The 2020 Census had much debate over a hotly contested question about citizenship.