Because of the way Census records were obtained, the spelling of names, the dates of events and other information may not be even vaguely correct. But sometimes even incorrect information can lead to more specific and accurate names and dates. It is common for beginning researchers to rely only upon the indexes to find their families. They conclude, incorrectly, that failure to appear in Ancestry.com's index is an indication that their family somehow got missed by the Census enumerators. Frequently, a page by page examination of the Census will show that the family was not missed, but simply recorded in way as to obscure the index entry.
Finding your ancestors in any census records, anywhere in the world, are really just the very first small step in researching records about your family. One huge value of finding your family in the census is the additional record searches suggested by the entries. This is also an important reason for finding the family and all the members of the family, in every single available census during their lifetimes. Beginning researchers often fail to follow up on the myriad of sources suggested by each census record.
My recent compilation of records for my Great-grandmother, Francis Ann Thomas (b. 1864, d. 1950), is a good example of both the benefits and the detriments of relying solely on U.S. Census records. Since Francis was born in 1864 and died in 1950, she should appear in every Census beginning in 1870 and ending with the most recent release in 1940. In each year the Census was taken, the questions asked changed, so there is a reason for finding the Census record for every year that may apply to your ancestor.
For example, here is a list of the important categories of genealogical information in the 1870 U.S. Federal Census:
- Full name
- Age (can be used to approximate birth year)
- Whether married during the previous year
- Town, township, or post office of residence
- Month of birth if born during the previous year
- Month of marriage if married during the previous year
- Whether the father and mother of each person was born in a foreign country
- Full name
- Age (can be used to calculate an approximate birth year)
- Birth month and year
- Relationship to the head of household
- Birthplace of the individual and the parents (included even if the parents were not members of the household)
- Marital status (single, married, widowed, or divorced)
- Number of years married (can be used to calculate the approximate marriage year)
- Number of children born to each mother and the number of those still living
- Year of immigration and number of years in the United States
- Whether a naturalized citizen
- Street address and house number
- Tribe and clan
- Date of locating to Alaska
- Occupation in Alaska
- Post office address at home
- Indian name
- Tribe of the individual and the parents (included even if the parents were not members of the household)
- Percentage of white blood
- If married, whether living in polygamy
- Whether taxed
- Year of citizenship
- Whether citizenship was acquired by land allotment
- Year of immigration and number of years lived in the Hawaiian Islands
- Name of military, naval station, or vessel
- Company or troop, regiment, and arm of service
- Rank grade or class
- Residence in the United States
Every single one of these entries may suggest further places to look for records.
Now, back to Frances Ann Thomas. Each of the Census records compiled during her lifetime is available. But that fact is neither obvious or easy to ascertain. For example, in the 1880 U.S. Census, the enumerator got her father's names reversed. His name was David Thomas, but it was recorded as Thomas Davids, so none of the indexes even come close to having his name or the name of his family members correct. It can be found, however, by a relatively short search of the small town the family lived in during that census year.
As you can see from the categories listed above, doing a census search for every year for every family member is far from redundant.