Different periods of U.S. history present various challenges.
Pre-1850
The first U.S. census to name every household member, not just the head, was 1850. Most places did not have civil registration until later. This is not a time period where you can easily conduct research by looking up the family in the census and finding everyone’s birth and death records.
You can find the head of household in the census and check the tick marks for the age groups of other household members. If you know your third-great-grandfather was three in 1830, you’d look up your fourth-great-grandfather’s name and check to see if there’s a three-year-old boy.
Probate records are invaluable in this time period because they usually name the heirs. Land and tax records are also helpful. These records reveal the identities of the neighbors, potentially indicating who could be relatives or in-laws.
Not all records will directly state who’s related to whom, so it’s often necessary to piece together bits of evidence from a variety of sources.
1850-1950
This is probably the easiest time period to research. Censuses are available for every decade except 1890, and they name every household member. Beginning in 1880, censuses indicated the relationship of each person to the head of household. From 1880 to 1930, censuses listed the parents’ birthplaces; some censuses also included immigration information, while others listed military information for veterans. The censuses from this century are rich in genealogical clues and are usually easy to find.
Many U.S. states began keeping vital records in the early 20th century. If your ancestor was born after their state began keeping birth certificates, you can order that for them. Some cities started recording births and deaths before the states did, so you might be lucky enough to get those records. Death certificates generally cover more ancestors. An ancestor born in the early 1800s who died after their state began keeping death certificates would have one. Additionally, privacy restrictions for birth records are usually much earlier than those of death records.
While censuses and vital records are more readily available for this time period, there was, in general, an increase in the number of records kept. The Social Security Administration was established in the early 20th century. Newspapers were printing bigger papers and more often. City directories became more regular.
1950-2000
This time period is actually more challenging to research than one might expect. The 2060 census won’t be available to the public until 2032. Privacy restrictions block access to vital records for much of this time, depending on the state. Some states will issue records only to immediate family members.
If your relatives from this time period are alive and you’re on speaking terms with them, an interview with them would be the best way to learn about their lives during this time.
However, this isn’t always an option, so you need to find records. In this case, you’ll want to rely on public records, such as city and telephone directories, and newspapers.
2000-present
21st-century research can implement social media. How much social media reveals about one’s family depends on how much they post and whether they identify relatives.