As I have mentioned before, accuracy is critical in genealogy. There are many genealogies-family histories, both in books and online, that have flaws (minor and major ones), so verifying information is crucial.
One reason they may be inaccurate is the lack of documentation. Vital records, which typically encompass birth, marriage, divorce and death records are primary sources, and often form the foundation of any accurate family history.
Religious institutions have kept these kinds of records for centuries, but in the late 1700s, a few European government entities started keeping civil records, which were often important for taxation and military purposes (Napoleon in France is one early example). Most governments didnt start until at least the 1850s, and a number in the US may not have begun until the early 1900s. This includes local, state and federal levels of government.
Information collected was rarely consistent from area to area, and tended to be sparse in the early days of collection. As time went on, forms became more standardized, and asked for more information.
Vital records not only verify an event, but often help you go back another generation (or help verify those generations.) Most birth certificates have the parents names, as do many marriage certificates. While death certificates usually ask that question, memories have faded of those who are giving information, and too often the information is spotty.
Be aware that although these records are generally regarded as true and accurate, is certainly not always the case.
Where can you get these records? Ill give you one of the most common answers in genealogy it depends. In this case, it depends on what level of government originally kept them, what time period were dealing with, and who has been designated the repository now for such records. Its always a good idea to start with the county, since they generally know where records are now kept.
Of course, before you can order any records, you need to know where to search. Take your best guess where the person was during the event youre looking to document. For example, you know your great-grandfather Abe died in Brooklyn, but was he born or married there? If he immigrated here, obviously he wasnt born here and theres a 50-50 chance that he was married here. Family stories are guides to those locations, but often come with a fair amount of distortion. If your ancestor was US born, then the census will tell you which state otherwise theyll tell you the country, but too often that turns out to say Russia (which almost always meant the Russian Empire, not Russia itself).
US vital records indexes (which are crucial) are just starting to come online, and some of the certificates themselves are also being scanned in digitally and becoming available. Most are still not, so often your choices are to order through an online service (vitalcheck.com is probably the leading commercial service), or contacting the repository directly and finding their procedure for ordering records. If in doubt, you can call the government offices you believe hold those records, and ask how to obtain them. Cydislist.com is good place to find where to contact (under United States Index.)
Vital records outside of the US deserve a separate column but know that they probably do exist, and more attainable than you may believe.