Now that you have found your ancestors (or yourself) in the 1940 U.S. Census, where can you go next to find more information? For the past ten years or so, the 1930 U.S. Census was the most recent place to relatively easily find families and individuals, some of whom were still alive. Finding information about the living or only recently deceased has always been a challenge. Now that the Census information has moved from 1930 up to 1940, once again there is a way to find people who may still be living without paying a premium to a skip-trace company.
But if you realize it, the 1940 U.S. Census itself suggests a lot of other places to search for additional information. Some of which is easily obtainable but some take considerable effort or payment. By 1940, a lot of information about individuals was beginning to be centralized in large databases. Many of those records have now been computerized or digitized.
By 1940, the huge shift in the U.S. population from rural communities to the cities was in full swing and people were beginning to move around more easily. World War II was almost a reality for the United States, with war raging or imminent in Europe, China and the Pacific. Without belaboring the point, you need to study the history and social climate of the 1940s to understand where to look for additional information about your families.
If you want a detailed list of types of records to search, look at the Resource Checklist in the FamilySearch Research Wiki. Take some time to think about each piece of information in the Census and where that information might lead you.
Where to start to analyze the Census for suggestions for additional information? That's also easy, you start with the Detailed Questions and Enumerator Instructions. Here are some of the topics in the questions and some suggestions for further searches:
The Census asked for street name and house number. The next place to go would be a directory either a telephone directory, a city directory or a business directory. City directories can often be found at local, state and national libraries. You might want to start with this page from the FamilySearch Research Wiki, "1940 Census United States - Using City Directories to Find a Street Address" and this page also, "United States Directories."
With a name and address, you can also research voting records, tax records, land and property ownership records, court records, utility records and many more. If you know the religious affiliation of your ancestors, you may also find church records from churches in the vicinity.
The Census asks whether or not the home is owned or rented? If the home is owned, you can look for land and property records. Try the county recorder of deeds in the county where you find the family. If the family lives on a farm, try looking for records and information on farm coops and other organizations such as the Farm Credit Administration.
Other than for general interest, personal information suggests when and where to look further for birth information. If the person was widowed, you can look for a death certificate of the deceased person. If someone was divorced, you look for the court records of the divorce.
By now you are probably getting the drift of how to use the Census to suggest other records. Education always suggests looking for school records.
Place of Birth
Always useful, the place of birth may not be too accurate but may be better than nothing. Obviously, you are on your way to look for immigration and naturalization records. The supplementary questions are also useful by providing the place of birth of the parents and their native language.
Residence in 1935
A lead to more interesting and useful records perhaps the sames ones you have already searched in the 1940 jurisdiction.
Work related questions
I suggest employment records, union records, WPA, CCC, and other public works project records.
Military records are usually more difficult to obtain and may be missing at times due to huge loss of records from the St. Louis, Missouri repository, but you can almost always find supplementary copies of some of the records.
Obtain Form 711 for the person's original application for Social Security.
Age at first marriage and number of children
Marriage and birth records are a natural. But also think about hospital records, school records and other records related to the family.
By 1940 the world was filling up with records and you are only limited by your imagination, background knowledge and persistence. Good Luck looking.