The first United States census records were collected for the year 1790. From 1790 to 1840 the records only showed the name of the head of each household and a tally of the number of persons in the household in broad age-groups. 

In 1840 the number of persons with a disability was added along with literacy status and pensioners from Revolutionary military service.

From 1850 to 1870 the records show the name of every single person counted in a household as well as additional information about each person not found earlier. Some of that information included place of birth, employment, value of estate, naturalization status, etc. The 1850 census included the first slave schedule. The 1860 census was the first to list Native Americans.

In 1880, the modern census began. Professional census workers, using special districts within regular state and county areas, did the enumerations.

A fire in 1921 destroyed 99% of the 1890 census records.

The 1900 census is regarded as one of the most inclusive and accurate of the federally created indexes.

By law, a 72-year restriction limits public access to all federal records. Therefore the last census available to the public at this time is 1950.

Spelling errors and incorrect transcriptions of names is very common in census records. The enumerators wrote what they heard and their writing could be hard to decipher.