Vital records are are highly informative primary resources. Birth certificates, marriage certificates, death certificates, divorce certificates, and adoption records include the full name of the individual(s), the date of the event, and the county, state, or town where the event occurred.
Birth records usually list the parents’ full names, name of the baby, date of the birth, and county where the birth took place. Marriage records often record the names and birthplaces of each individual's parents. Divorce records usually list the names of the couple's children. Death certificates often mention the burial site and provide the name of the individual who reported the death.
Vital records are maintained at the state and county levels. A good starting place to look for vital records is at the county courthouse where the person(s) you're researching lived at the time of the event.
Prior to the 1860s, registering family events (births, marriages, deaths) was voluntary. Some early settlers traveled by horse to the county seat to register births, marriages, deaths, naturalizations, and land sales. But since these trips could be long, they chose to make them infrequently, resulting in spotty and incomplete records After requirements to vote were made mandatory, record-keeping became more frequent. If you are having difficulty locating a relative prior to 1860, this could be the reason.