In the US this tends to be done at the city or county level, as far as I know. In my state each city has their own land parcel database that they make available

In the US this tends to be done at the city or county level, as far as I know. In my state each city has their own land parcel database that they make available. That said, this commenter pointed to https://regrid.com https://regrid.com as a company that aggregates all this local data and provides a nationwide parcel map - https://news.ycombinator.com/item?id=33755133 https://news.ycombinator.com/item?id=33755133. Regrid looks great and might work for you.