Early in the history of America, the church played a critical role in recording vital records. These recordkeeping practices were brought with them from the old country where the state church was required by law to record details on all citizens of the realm. After the American Revolution, these practices changed over time. However, it was not until the 1900s that most states began to record births and deaths as mandated by law. Therefore, searching the church records is necessary to build your family tree more accurately. This Research Guide will give you details on how religious unrest in Europe affected migrations to America; in-depth details on why church records are important to your research; methods of tracing hard-to-find ancestors by religion; background information about non-conformist religions; sources for researching in the British Isles and Europe; instruction on how to use the evidence to trace and prove family relationships and migrations; and an introduction to large religious collections, some of which can be accessed online.