For some immigrants, the complete birth date, along with their correct, full name, is often enough to correctly identify an immigrant. If a source in North America says that Jakob de Jager was born on 14 November 1819, he may be the only one in his country with that exact name and birth date. In other cases even that will not be enough, but it will certainly keep us as researchers from connecting our family to another person of the same name born on a different date in 1819, or even in 1820. However, such false linkages would be common problems if we relied only on, say, a census record providing the age of an immigrant as a substitute for his or her birth date. Where, then, do you find an exact birth date? Generally, you will find these on records dealing with the immigrant's death. This, of course, happened in his or her new country or else they would not be an immigrant. Cemetery inscriptions and death or burial records are some of the best sources for this information. A biographical sketch or obituary often gives a person's exact date of birth. Also consider other records that seek to fully identify a person, such as pension records (for the military or private businesses). Family Bibles often include exact birth dates, but locating ones that are not owned by your known family members can be difficult. Compiled records about the immigrant and his or her family, such as genealogies and periodical articles, may also include an exact birth date. Census records are not a good substitute for this information. Even the 1900 U.S. census, which provides the month and year of birth is often incorrect. Probate and land records seldom include such identification. Neither do passenger lists. Naturalization records may provide the information, but generally only in more recent years. The same is true of civil marriage records.