For the dates of each of the events in your ancestors' life, always record the precise location as it existed at the time of the event. That includes birth, marriage, divorce, censuses, military service, land and property transactions, date of will, death, probate, and more. Record the town, the county or parish, and the state for U.S. events. Record early American locations as “British Colony”, “French Colony”, “Spanish Colony, etc., for events that occurred in locations while they were under governmental control of those countries. For foreign locations, list the town, province and county, and country at the time.
Remember that, because boundaries and jurisdictions changed so much over time, you should be certain you have the correct county or state, or province or country listed as it existed when the event occurred. Refer to printed histories of an area to help clarify dates of governmental control and of boundary changes. Use old printed atlases, digitized historical maps online, and gazetteers/place name dictionaries can be invaluable in locating places, especially if names have changed or a place no longer exists.
This work will be important to you for purposes of locating copies of records any time you seek them for an ancestor’s life and for understanding context. It is also important for future researchers who want to confirm your research and obtain copies for themselves to review and analyze.