Vital Records in Massachusetts
In Massachusetts, the original vital records (of births, marriages, and deaths) have been created and maintained by the town or city in which the event occurred. In very early colonial times, copies of these records were submitted to the county, but that practice died out long before 1700. There were marriage intentions commonly recorded in the bride's home town and additional recordings maybe found in the groom's home town and their current residence.
Massachusetts was the first state to bring a unified state-level recording of these events (but not marriage intentions) in 1841 (Boston excluded until 1850). The associated records of divorce and adoption are handled by the courts. The state has maintained a state-wide index to divorces since 1952, but adoption records will require more researching to discover.
It is easiest to start with the state vital records for events since 1841, though realize the original record is with the town or city. More details can be found on the Massachusetts Vital Records page.