The title of the database is “YourFavoriteState Marriage Records 1820-1900.” Don’t assume the entire state or province is covered for the entire time period listed in the title. That range of years may start with the earliest record included and end with the last year of one record. There may be counties or areas whose records are extant and completely included in the database for the entire 1820-1900 time period.
There may be counties whose records cover the entire 1820-1900 time period but where there are significant gaps. There may be counties whose records in the database only include 1830-1870. There may be counties that have no records included at all.
It’s up to you to find out. That may be in the “more about” or Frequently Asked Questions page. It may also be buried underneath the search boxes on the search page.
But find out what the coverage is for the region of the state or province. Don’t assume coverage is complete.